Trial Outcomes & Findings for Cladribine With Simultaneous or Delayed Rituximab to Treat Hairy Cell Leukemia (NCT NCT00923013)

Last Updated: 2025-08-08

Results Overview

Participants with newly diagnosed Hairy Cell Leukemia (HCL) and once relapsed HCL were split and both groups were randomized to receive either simultaneous treatment with Cladribine and Rituxan or Cladribine with Rituxan given no earlier than 6 months after cladribine as needed. Outcome measured by Bone Marrow and Blood Flow cytometry and histochemistry of the core biopsy at the 6 months after start of treatment time point. If all three were negative for hairy cells participants were in a minimal residual disease status (MRD). And were considered without HCL disease at that time point.

Recruitment status

ACTIVE_NOT_RECRUITING

Study phase

PHASE2

Target enrollment

175 participants

Primary outcome timeframe

Restaged 6 months after the start of treatment

Results posted on

2025-08-08

Participant Flow

Participant milestones

Participant milestones
Measure	Cohort 1 Arm 1 SubGroup 1 -Cladribine + Rituximab Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 1 SubGroup 2 -Cladribine + Rituximab Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 2 SubGroup 1-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 1 Arm 2 SubGroup 2-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 2 Arm 3 SubGroup 1-Cladribine (Rituximab Before 1st of 5 Daily Doses of Cladribine on Day 1) Participants with Hairy Cell Leukemia (HCL) without prior course of purine analog to be directly assigned to Arm 3 (25 participants; after completion of the 68 participants without prior purine analog in Cohort 1). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine	Cohort 3Arm3 HairyCell LeukemiaVariant-Cladribine +(Rituximab Before 1st of 5 Daily Doses Cladribine Participants with Hairy Cell Leukemia Variant (HCLv) to be directly assigned to Arm 3 (20 participants). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine
Overall Study STARTED	34	32	34	30	25	20
Overall Study Disease Progression on Study	1	0	0	0	0	4
Overall Study Refused Further Follow-up	1	0	0	0	0	0
Overall Study Death During Follow-up Period	0	0	0	0	0	2
Overall Study COMPLETED	32	28	32	29	25	20
Overall Study NOT COMPLETED	2	4	2	1	0	0

Reasons for withdrawal

Reasons for withdrawal
Measure	Cohort 1 Arm 1 SubGroup 1 -Cladribine + Rituximab Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 1 SubGroup 2 -Cladribine + Rituximab Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 2 SubGroup 1-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 1 Arm 2 SubGroup 2-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).
Overall Study Refused further treatment	0	1	2	0
Overall Study Switched to alternative treatment	0	1	0	0
Overall Study Death on study	2	2	0	1

Baseline Characteristics

Cladribine With Simultaneous or Delayed Rituximab to Treat Hairy Cell Leukemia

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Cohort 1 Arm 1 SubGroup 1 -Cladribine + Rituximab n=34 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 1 SubGroup 2 -Cladribine + Rituximab n=32 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 2 SubGroup 1-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=34 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 1 Arm 2 SubGroup 2-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=30 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 2 Arm 3 SubGroup 1-Cladribine (Rituximab Before 1st of 5 Daily Doses of Cladribine on Day 1) n=25 Participants Participants with Hairy Cell Leukemia (HCL) without prior course of purine analog to be directly assigned to Arm 3 (25 participants; after completion of the 68 participants without prior purine analog in Cohort 1). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine	Cohort 3Arm3 HairyCell LeukemiaVariant-Cladribine +(Rituximab Before 1st of 5 Daily Doses Cladribine n=20 Participants Participants with Hairy Cell Leukemia Variant (HCLv) to be directly assigned to Arm 3 (20 participants). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine	Total n=175 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	0 Participants n=115 Participants
Age, Categorical Between 18 and 65 years	29 Participants n=5 Participants	28 Participants n=7 Participants	31 Participants n=5 Participants	27 Participants n=4 Participants	19 Participants n=21 Participants	9 Participants n=10 Participants	143 Participants n=115 Participants
Age, Categorical >=65 years	5 Participants n=5 Participants	4 Participants n=7 Participants	3 Participants n=5 Participants	3 Participants n=4 Participants	6 Participants n=21 Participants	11 Participants n=10 Participants	32 Participants n=115 Participants
Age, Continuous	51.03 years STANDARD_DEVIATION 11.8 • n=5 Participants	54.56 years STANDARD_DEVIATION 10.23 • n=7 Participants	47.94 years STANDARD_DEVIATION 11.19 • n=5 Participants	51.83 years STANDARD_DEVIATION 10.62 • n=4 Participants	53.16 years STANDARD_DEVIATION 13.85 • n=21 Participants	64.7 years STANDARD_DEVIATION 11.75 • n=10 Participants	53.08 years STANDARD_DEVIATION 12.3 • n=115 Participants
Sex: Female, Male Female	8 Participants n=5 Participants	2 Participants n=7 Participants	5 Participants n=5 Participants	6 Participants n=4 Participants	6 Participants n=21 Participants	5 Participants n=10 Participants	32 Participants n=115 Participants
Sex: Female, Male Male	26 Participants n=5 Participants	30 Participants n=7 Participants	29 Participants n=5 Participants	24 Participants n=4 Participants	19 Participants n=21 Participants	15 Participants n=10 Participants	143 Participants n=115 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants n=5 Participants	2 Participants n=7 Participants	5 Participants n=5 Participants	2 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	11 Participants n=115 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	0 Participants n=5 Participants	29 Participants n=7 Participants	26 Participants n=5 Participants	28 Participants n=4 Participants	25 Participants n=21 Participants	20 Participants n=10 Participants	128 Participants n=115 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	32 Participants n=5 Participants	1 Participants n=7 Participants	3 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	36 Participants n=115 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	0 Participants n=115 Participants
Race (NIH/OMB) Asian	2 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	3 Participants n=115 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	0 Participants n=115 Participants
Race (NIH/OMB) Black or African American	1 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	0 Participants n=21 Participants	1 Participants n=10 Participants	3 Participants n=115 Participants
Race (NIH/OMB) White	30 Participants n=5 Participants	32 Participants n=7 Participants	30 Participants n=5 Participants	26 Participants n=4 Participants	25 Participants n=21 Participants	18 Participants n=10 Participants	161 Participants n=115 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	1 Participants n=115 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	0 Participants n=7 Participants	4 Participants n=5 Participants	1 Participants n=4 Participants	0 Participants n=21 Participants	1 Participants n=10 Participants	7 Participants n=115 Participants
Region of Enrollment United States	34 participants n=5 Participants	32 participants n=7 Participants	34 participants n=5 Participants	30 participants n=4 Participants	25 participants n=21 Participants	20 participants n=10 Participants	175 participants n=115 Participants

PRIMARY outcome

Timeframe: Restaged 6 months after the start of treatment

Population: Cohort 2, Arm 3 and Cohort 3, Arm 3 are not reported because the investigator is only comparing the randomized groups. The primary goal is comparing the randomization and Cohort 2 was not randomized.

Outcome measures

Outcome measures
Measure	Cohort 1 Arm 1 SubGroup 1 -Cladribine + Rituximab n=34 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 1 SubGroup 2 -Cladribine + Rituximab n=32 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 2 SubGroup 1-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=34 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 1 Arm 2 SubGroup 2-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=30 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 2 Arm 3 SubGroup 1-Cladribine (Rituximab Before 1st of 5 Daily Doses of Cladribine on Day 1) Participants with Hairy Cell Leukemia (HCL) without prior course of purine analog to be directly assigned to Arm 3 (25 participants; after completion of the 68 participants without prior purine analog in Cohort 1). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine	Cohort 3Arm3 HairyCell LeukemiaVariant-Cladribine +(Rituximab Before 1st of 5 Daily Doses Cladribine Participants with Hairy Cell Leukemia Variant (HCLv) to be directly assigned to Arm 3 (20 participants). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine
Response Rate Comparing Minimal Residual Disease (MRD) at 6 Months After Start of Treatment in Comparison Groups	97.1 Percentage of participants	62.5 Percentage of participants	23.5 Percentage of participants	3.3 Percentage of participants	—	—

SECONDARY outcome

Timeframe: Testing done 6 months post first dose of treatment, then yearly x2 years and then every 2 years after cladribine indefinitely

Compare Cladribine + Rituxan vs cladribine alone in terms of MRD-free survival. MRD free survival time is the time until relapsing from MRD to -free to Complete response. Measured by blood and bone marrow flow cytometry, complete blood count (CBC), and bone marrow immunohistochemistry.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: From first study intervention,Study Day 1, Cycle 1-30 days after study agent up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine+rituximab, &up to day 80 for participants receiving delayed rituximab.

Here is the number of participants with serious and/or non-serious adverse events (AE's) assessed by the Common Terminology Criteria for Adverse Events (CTCAE v3.0). A non-serious adverse event is any untoward medical occurrence. A serious adverse event is an adverse event or suspected adverse reaction that results in death, a life-threatening adverse drug experience, hospitalization, disruption of the ability to conduct normal life functions, congenital anomaly/birth defect or important medical events that jeopardize the patient or subject and may require medical or surgical intervention to prevent one of the previous outcomes mentioned.

Outcome measures

Outcome measures
Measure	Cohort 1 Arm 1 SubGroup 1 -Cladribine + Rituximab n=34 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 1 SubGroup 2 -Cladribine + Rituximab n=32 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 2 SubGroup 1-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=34 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 1 Arm 2 SubGroup 2-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=30 Participants Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (randomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 2 Arm 3 SubGroup 1-Cladribine (Rituximab Before 1st of 5 Daily Doses of Cladribine on Day 1) n=25 Participants Participants with Hairy Cell Leukemia (HCL) without prior course of purine analog to be directly assigned to Arm 3 (25 participants; after completion of the 68 participants without prior purine analog in Cohort 1). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine	Cohort 3Arm3 HairyCell LeukemiaVariant-Cladribine +(Rituximab Before 1st of 5 Daily Doses Cladribine n=20 Participants Participants with Hairy Cell Leukemia Variant (HCLv) to be directly assigned to Arm 3 (20 participants). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine
Number of Participants With Serious and/or Non-serious Adverse Events Assessed by the Common Terminology Criteria for Adverse Events (CTCAEv3.0)	34 Participants	31 Participants	34 Participants	29 Participants	24 Participants	19 Participants

Adverse Events

Cohort 1 Arm 1 SubGroup 1 -Cladribine + Rituximab

Serious events: 4 serious events

Other events: 34 other events

Deaths: 2 deaths

Cohort 1 Arm 1 SubGroup 2 -Cladribine + Rituximab

Serious events: 2 serious events

Other events: 31 other events

Deaths: 2 deaths

Cohort 1 Arm 2 SubGroup 1-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected)

Serious events: 2 serious events

Other events: 34 other events

Deaths: 0 deaths

Cohort 1 Arm 2 SubGroup 2-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected)

Serious events: 5 serious events

Other events: 29 other events

Deaths: 1 deaths

Cohort 2 Arm 3 SubGroup 1-Cladribine (Rituximab Before 1st of 5 Daily Doses of Cladribine on Day 1)

Serious events: 4 serious events

Other events: 24 other events

Deaths: 0 deaths

Cohort 3Arm3 HairyCell LeukemiaVariant-Cladribine +(Rituximab Before 1st of 5 Daily Doses Cladribine

Serious events: 3 serious events

Other events: 19 other events

Deaths: 5 deaths

Serious adverse events

Serious adverse events
Measure	Cohort 1 Arm 1 SubGroup 1 -Cladribine + Rituximab n=34 participants at risk Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (ramdomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 1 SubGroup 2 -Cladribine + Rituximab n=32 participants at risk Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (ramdomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 2 SubGroup 1-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=34 participants at risk Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (ramdomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 1 Arm 2 SubGroup 2-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=30 participants at risk Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (ramdomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 2 Arm 3 SubGroup 1-Cladribine (Rituximab Before 1st of 5 Daily Doses of Cladribine on Day 1) n=25 participants at risk Participants with Hairy Cell Leukemia (HCL) without prior course of purine analog to be directly assigned to Arm 3 (25 participants; after completion of the 68 participants without prior purine analog in Cohort 1). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine	Cohort 3Arm3 HairyCell LeukemiaVariant-Cladribine +(Rituximab Before 1st of 5 Daily Doses Cladribine n=20 participants at risk Participants with Hairy Cell Leukemia Variant (HCLv) to be directly assigned to Arm 3 (20 participants). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine
Cardiac disorders Cardiac ischemia/infarction	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Creatinine	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Death not associated with CTCAE term::Death NOS	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Death not associated with CTCAE term::Disease progression NOS	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Diarrhea	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Dyspnea (shortness of breath)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Fatigue (asthenia, lethargy, malaise)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Febrile neutropenia	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.0% 3/25 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Hypertension	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Hypotension	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Hypoxia	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Wound	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with unknown ANC::Lung (pneumonia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Nausea	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Neutrophils/granulocytes (ANC/AGC)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain::Joint	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.

Other adverse events

Other adverse events
Measure	Cohort 1 Arm 1 SubGroup 1 -Cladribine + Rituximab n=34 participants at risk Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (ramdomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 1 SubGroup 2 -Cladribine + Rituximab n=32 participants at risk Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (ramdomization stratified based upon prior purine analog \[yes/no\]). Cladribine + Rituximab.	Cohort 1 Arm 2 SubGroup 1-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=34 participants at risk Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (ramdomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 1 Arm 2 SubGroup 2-Cladribine(+Rituximab After 6 Months if Minimal Residual Disease Detected) n=30 participants at risk Participants with Hairy Cell Leukemia (HCL) with (62 participants) and without (68 participants) prior course of purine analog to be randomized between Arm 1 and Arm 2 (ramdomization stratified based upon prior purine analog \[yes/no\]). Cladribine (+ Rituximab after 6 months if minimal residual disease (MRD) detected).	Cohort 2 Arm 3 SubGroup 1-Cladribine (Rituximab Before 1st of 5 Daily Doses of Cladribine on Day 1) n=25 participants at risk Participants with Hairy Cell Leukemia (HCL) without prior course of purine analog to be directly assigned to Arm 3 (25 participants; after completion of the 68 participants without prior purine analog in Cohort 1). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine	Cohort 3Arm3 HairyCell LeukemiaVariant-Cladribine +(Rituximab Before 1st of 5 Daily Doses Cladribine n=20 participants at risk Participants with Hairy Cell Leukemia Variant (HCLv) to be directly assigned to Arm 3 (20 participants). Cladribine + Rituximab (Rituximab will be administered just before rather than after the 1st of the 5 daily doses of cladribine
Metabolism and nutrition disorders Calcium, serum-high (hypercalcemia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Pain::Cardiac/heart	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Calcium, serum-low (hypocalcemia)	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 6/30 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders ALT, SGPT (serum glutamic pyruvic transaminase)	41.2% 14/34 • Number of events 16 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	26.5% 9/34 • Number of events 10 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.7% 5/30 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.0% 4/25 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	15.0% 3/20 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders AST, SGOT(serum glutamic oxaloacetic transaminase)	35.3% 12/34 • Number of events 13 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	29.4% 10/34 • Number of events 11 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 5/25 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	30.0% 6/20 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Albumin, serum-low (hypoalbuminemia)	32.4% 11/34 • Number of events 11 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	21.9% 7/32 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	29.4% 10/34 • Number of events 13 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	33.3% 10/30 • Number of events 10 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.0% 4/25 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	30.0% 6/20 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Alkaline phosphatase	17.6% 6/34 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Immune system disorders Allergic reaction/hypersensitivity (including drug fever)	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Immune system disorders Allergic rhinitis (including sneezing, nasal stuffiness, postnasal drip)	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	15.0% 3/20 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Anorexia	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Bicarbonate, serum-low	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 5/25 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Bilirubin (hyperbilirubinemia)	11.8% 4/34 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.5% 4/32 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	14.7% 5/34 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.7% 5/30 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Bronchospasm, wheezing	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Bruising (in absence of Grade 3 or 4 thrombocytopenia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders CD4 count	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.0% 4/25 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders CPK (creatine phosphokinase)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Cardiac Arrhythmia - Other (Specify: Sinus Tachycardia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Cardiac Arrhythmia - Other (Specify: Systolic hypertension)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Cardiac General - Other (Specify: Sinus tachycardia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Conjunctiva	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Cardiac troponin I (cTnI)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Cheilitis	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Hepatobiliary disorders Cholecystitis	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Cholesterol, serum-high (hypercholesteremia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Constipation	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.0% 4/25 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Constitutional Symptoms - Other (Specify: Joint-effusion)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Cough	11.8% 4/34 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	15.6% 5/32 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	17.6% 6/34 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.7% 5/30 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 4/20 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Creatinine	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Immune system disorders Cytokine release syndrome/acute infusion reaction	55.9% 19/34 • Number of events 21 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	11.8% 4/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Diarrhea	11.8% 4/34 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	11.8% 4/34 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 3/30 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Distension/bloating, abdominal	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Dizziness	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Dry mouth/salivary gland (xerostomia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Dry skin	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Dyspnea (shortness of breath)	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 4/20 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Edema: limb	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Extremity-lower (gait/walking)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Extremity-upper (function)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Eye disorders Eyelid dysfunction	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders FEV(1)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.0% 3/25 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Fatigue (asthenia, lethargy, malaise)	14.7% 5/34 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	23.5% 8/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	13.3% 4/30 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.0% 3/25 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 4/20 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Febrile neutropenia	32.4% 11/34 • Number of events 11 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	23.5% 8/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.0% 4/25 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Fever (in the absence of neutropenia, where neutropenia is defined as ANC <1.0 x 10e9/L)	41.2% 14/34 • Number of events 14 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	25.0% 8/32 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	17.6% 6/34 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 6/30 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 4/20 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Fibrinogen	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Flu-like syndrome	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Flushing	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders GGT (gamma-Glutamyl transpeptidase)	11.8% 4/34 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Glucose, serum-high (hyperglycemia)	35.3% 12/34 • Number of events 12 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	28.1% 9/32 • Number of events 12 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	14.7% 5/34 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	30.0% 9/30 • Number of events 11 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 4/20 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Glucose, serum-low (hypoglycemia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Hair loss/alopecia (scalp or body)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Haptoglobin	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 3/30 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Heartburn/dyspepsia	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Hematoma	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Hemoglobin	44.1% 15/34 • Number of events 24 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	43.8% 14/32 • Number of events 21 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	38.2% 13/34 • Number of events 15 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	46.7% 14/30 • Number of events 20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	48.0% 12/25 • Number of events 25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	25.0% 5/20 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Hemoglobinuria	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Hemorrhage, GI::Rectum	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Renal and urinary disorders Hemorrhage, GU::Urinary NOS	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 4/20 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Hemorrhage, pulmonary/upper respiratory::Larynx	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Hemorrhage, pulmonary/upper respiratory::Nose	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Hemorrhage/Bleeding - Other (Specify: Epistaxis)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Hemorrhage/Bleeding - Other (Specify: Macular)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Hemorrhoids	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Hyperpigmentation	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Hypertension	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Hypotension	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Hypoxia	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders INR (International Normalized Ratio of prothrombin time)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection - Other (Specify: Pneumonia)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Abdomen NOS	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Muscle (infection myositis)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Oral cavity-gums (gingivitis)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Penis	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Sinus	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Skin (cellulitis)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Spleen	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with normal ANC or Grade 1 or 2 neutrophils::Wound	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Infections and infestations Infection with unknown ANC::Upper airway NOS	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Injection site reaction/extravasation changes	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Insomnia	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 4/20 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Left ventricular systolic dysfunction	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Leukocytes (total WBC)	70.6% 24/34 • Number of events 39 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	65.6% 21/32 • Number of events 30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	82.4% 28/34 • Number of events 43 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	56.7% 17/30 • Number of events 22 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 5/25 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	45.0% 9/20 • Number of events 9 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Lipase	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Lymphatics - Other (Specify: Edema/ankles)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Lymphatics - Other (Specify: Edema: head-and-neck)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Lymphopenia	82.4% 28/34 • Number of events 45 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	68.8% 22/32 • Number of events 42 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	85.3% 29/34 • Number of events 44 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	70.0% 21/30 • Number of events 39 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 5/25 • Number of events 10 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	70.0% 14/20 • Number of events 18 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Magnesium, serum-high (hypermagnesemia)	11.8% 4/34 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 3/30 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Magnesium, serum-low (hypomagnesemia)	23.5% 8/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.5% 4/32 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	26.5% 9/34 • Number of events 9 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	15.0% 3/20 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Mood alteration::Anxiety	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Mucositis/stomatitis (clinical exam)::Oral cavity	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Mucositis/stomatitis (functional/symptomatic)::Oral cavity	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Nausea	20.6% 7/34 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	18.8% 6/32 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.6% 7/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	13.3% 4/30 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	35.0% 7/20 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Neurology - Other (Specify: Dizziness)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Neuropathy: cranial::CN II Vision	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Neuropathy: cranial::CN VIII Hearing and balance	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Neuropathy: sensory	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Neutrophils/granulocytes (ANC/AGC)	41.2% 14/34 • Number of events 21 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	43.8% 14/32 • Number of events 14 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	55.9% 19/34 • Number of events 25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	50.0% 15/30 • Number of events 21 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	25.0% 5/20 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders PTT (Partial Thromboplastin Time)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain - Other (Specify: Extremity-Limb)	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain - Other (Specify: Extremity-limb, related to BMBx)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain - Other (Specify: Extremity/Limb)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain - Other (Specify: RE limb)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Renal and urinary disorders Pain - Other (Specify: with urination)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Pain::Abdomen NOS	17.6% 6/34 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.6% 7/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	15.0% 3/20 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain::Back	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.5% 4/32 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain::Bone	17.6% 6/34 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Pain::Chest wall	11.8% 4/34 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Pain::Esophagus	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain::Extremity-limb	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Eye disorders Pain::Eye	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Pain::Face	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Pain::Head/headache	32.4% 11/34 • Number of events 11 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	21.9% 7/32 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	32.4% 11/34 • Number of events 12 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	13.3% 4/30 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.0% 3/25 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	15.0% 3/20 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain::Joint	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.7% 5/30 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	15.0% 3/20 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain::Muscle	26.5% 9/34 • Number of events 11 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.5% 4/32 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	20.0% 4/20 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Musculoskeletal and connective tissue disorders Pain::Neck	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Pain::Neuralgia/peripheral nerve	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Pain::Oral cavity	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Pain::Rectum	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Reproductive system and breast disorders Pain::Scrotum	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Pain::Throat/pharynx/larynx	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Reproductive system and breast disorders Pain::Urethra	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Palpitations	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Vascular disorders Phlebitis (including superficial thrombosis)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Phosphate, serum-low (hypophosphatemia)	38.2% 13/34 • Number of events 15 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	28.1% 9/32 • Number of events 10 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	14.7% 5/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	23.3% 7/30 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.0% 4/25 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Photosensitivity	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Blood and lymphatic system disorders Platelets	70.6% 24/34 • Number of events 29 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	53.1% 17/32 • Number of events 24 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	17.6% 6/34 • Number of events 11 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	23.3% 7/30 • Number of events 12 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	24.0% 6/25 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	45.0% 9/20 • Number of events 9 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Pleural effusion (non-malignant)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Respiratory, thoracic and mediastinal disorders Pneumothorax	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Potassium, serum-high (hyperkalemia)	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	15.0% 3/20 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Potassium, serum-low (hypokalemia)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Prolonged QTc interval	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Pruritus/itching	23.5% 8/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.5% 4/32 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	23.5% 8/34 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 3/30 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Rash/desquamation	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Rash: acne/acneiform	41.2% 14/34 • Number of events 15 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.5% 4/32 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	47.1% 16/34 • Number of events 16 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	13.3% 4/30 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	12.0% 3/25 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	30.0% 6/20 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Rash: dermatitis associated with radiation::Chemoradiation	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Rash: erythema multiforme (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Skin and subcutaneous tissue disorders Rash: hand-foot skin reaction	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Renal and urinary disorders Renal/Genitourinary - Other (Specify: Hyperuricemia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Right ventricular dysfunction (cor pulmonale)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Rigors/chills	50.0% 17/34 • Number of events 19 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	28.1% 9/32 • Number of events 9 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	26.5% 9/34 • Number of events 11 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	13.3% 4/30 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	36.0% 9/25 • Number of events 10 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	40.0% 8/20 • Number of events 8 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Sodium, serum-high (hypernatremia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Sodium, serum-low (hyponatremia)	14.7% 5/34 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.2% 2/32 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	14.7% 5/34 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	13.3% 4/30 • Number of events 4 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Supraventricular and nodal arrhythmia::Atrial tachycardia/Paroxysmal Atrial Tachycardia	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Supraventricular and nodal arrhythmia::Sinus arrhythmia	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Supraventricular and nodal arrhythmia::Sinus tachycardia	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Supraventricular and nodal arrhythmia::Supraventricular arrhythmia NOS	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Sweating (diaphoresis)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	17.6% 6/34 • Number of events 7 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	16.7% 5/30 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.0% 2/25 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	10.0% 2/20 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Nervous system disorders Syncope (fainting)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Taste alteration (dysgeusia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Vascular disorders Thrombosis/embolism (vascular access-related)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Endocrine disorders Thyroid function, low (hypothyroidism)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Ear and labyrinth disorders Tinnitus	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Triglyceride, serum-high (hypertriglyceridemia)	17.6% 6/34 • Number of events 6 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	6.7% 2/30 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Tumor lysis syndrome	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Metabolism and nutrition disorders Uric acid, serum-high (hyperuricemia)	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Renal and urinary disorders Urinary frequency/urgency	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Renal and urinary disorders Urinary retention (including neurogenic bladder)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Reproductive system and breast disorders Vaginitis (not due to infection)	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Vasovagal episode	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Cardiac disorders Ventricular arrhythmia::Ventricular tachycardia	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Eye disorders Vision-blurred vision	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.1% 1/32 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	2.9% 1/34 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/20 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
Gastrointestinal disorders Vomiting	5.9% 2/34 • Number of events 2 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	9.4% 3/32 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	8.8% 3/34 • Number of events 3 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	3.3% 1/30 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	4.0% 1/25 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	25.0% 5/20 • Number of events 5 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.
General disorders Weight gain	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/32 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/34 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/30 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	0.00% 0/25 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.	5.0% 1/20 • Number of events 1 • All-Cause Mortality was monitored/assessed up to 16 years. Adverse Events was monitored/assessed from the first study intervention, Study Day 1 of Cycle 1 through 30 days after the study agent, up to day 35 for participants receiving cladribine only, up to day 80 for participants receiving cladribine plus rituximab, and up to day 80 for participants receiving delayed rituximab.

Additional Information

Dr. Robert Kreitman

National Cancer Institute

Phone: 301-648-7375

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place