Trial Outcomes & Findings for A Phase II Trial of Ofatumumab in Subjects With Waldenstrom's Macroglobulinemia (NCT NCT00811733)

Last Updated: 2017-05-30

Results Overview

OR (based on the Consensus Panel recommendations from the 2nd and 3rd International Workshop on WM) included Complete Response (CR), Partial Response (PR), or a Minor Response (MR). CR: Complete disappearance of serum monoclonal (SM) Immunoglobulin (Ig) E (IgE), measured centrally; resolution of adenopathy/organomegaly upon physical exam and computerized tomography (CT) scan; lymph nodes =\<1.5 centimeters; absence of malignant cell by bone marrow histologic examination. PR: a \>=50% reduction from baseline in the SM IgM concentration. MR: \>=25%, but a \<50% reduction of SM IgM from baseline.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

37 participants

Primary outcome timeframe

Baseline and up to 27 months from the first dose of Cycle 1 (Study Day 1), and before Cycle 2 treatment

Results posted on

2017-05-30

Participant Flow

Participant milestones

Participant milestones
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Overall Study STARTED	15	22
Overall Study COMPLETED	4	12
Overall Study NOT COMPLETED	11	10

Reasons for withdrawal

Reasons for withdrawal
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Overall Study Investigator Discretion	10	8
Overall Study Withdrawal by Subject	1	2

Baseline Characteristics

A Phase II Trial of Ofatumumab in Subjects With Waldenstrom's Macroglobulinemia

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.	Total n=37 Participants Total of all reporting groups
Age, Continuous	62.3 Years STANDARD_DEVIATION 10.78 • n=5 Participants	64.0 Years STANDARD_DEVIATION 9.36 • n=7 Participants	63.3 Years STANDARD_DEVIATION 9.85 • n=5 Participants
Sex: Female, Male Female	6 Participants n=5 Participants	9 Participants n=7 Participants	15 Participants n=5 Participants
Sex: Female, Male Male	9 Participants n=5 Participants	13 Participants n=7 Participants	22 Participants n=5 Participants
Race/Ethnicity, Customized African American/African Heritage	0 participants n=5 Participants	1 participants n=7 Participants	1 participants n=5 Participants
Race/Ethnicity, Customized Asian - East Asian Heritage	0 participants n=5 Participants	1 participants n=7 Participants	1 participants n=5 Participants
Race/Ethnicity, Customized White - White/Caucasian/European	14 participants n=5 Participants	19 participants n=7 Participants	33 participants n=5 Participants
Race/Ethnicity, Customized Unknown	1 participants n=5 Participants	1 participants n=7 Participants	2 participants n=5 Participants

PRIMARY outcome

Timeframe: Baseline and up to 27 months from the first dose of Cycle 1 (Study Day 1), and before Cycle 2 treatment

Population: Intent-to-Treat (ITT) Population: all participants who were considered eligible for treatment and who had been exposed to study drug irrespective of the planned course of treatment.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With Overall Response (OR) for Cycle 1 (Including the Redosing Cycle), as Assessed by the Investigator	7 participants	15 participants

PRIMARY outcome

Timeframe: Baseline and up to Study Week 16

Population: ITT Population

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With OR for Cycle 1 (Excluding the Redosing Cycle), as Assessed by the Investigator	5 participants	14 participants

SECONDARY outcome

Timeframe: Baseline and up to 27 months from the first dose of Cycle 1 (Study Day 1), and before Cycle 2 treatment

Population: ITT Population

Response criteria were based on the Consensus Panel recommendations from the 2nd and 3rd International Workshop on WM. CR: Complete disappearance of serum monoclonal (SM) Immunoglobulin (Ig) E (IgE), measured centrally; resolution of adenopathy/organomegaly upon physical exam and computerized tomography (CT) scan; lymph nodes =\<1.5 centimeters; absence of malignant cell by bone marrow histologic examination. PR: a \>=50% reduction from baseline in the SM IgM concentration. MR: \>=25%, but a \<50% reduction of SM IgM from baseline.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With CR, PR, and MR for Cycle 1 (Including the Redosing Cycle), as Assessed by the Investigator CR	0 participants	0 participants
Number of Participants With CR, PR, and MR for Cycle 1 (Including the Redosing Cycle), as Assessed by the Investigator PR	4 participants	11 participants
Number of Participants With CR, PR, and MR for Cycle 1 (Including the Redosing Cycle), as Assessed by the Investigator MR	3 participants	4 participants

SECONDARY outcome

Timeframe: Baseline and up to Study Week 16

Population: ITT Population

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With CR, PR, and MR for Cycle 1 (Excluding the Redosing Cycle), as Assessed by the Investigator CR	0 participants	0 participants
Number of Participants With CR, PR, and MR for Cycle 1 (Excluding the Redosing Cycle), as Assessed by the Investigator PR	3 participants	9 participants
Number of Participants With CR, PR, and MR for Cycle 1 (Excluding the Redosing Cycle), as Assessed by the Investigator MR	2 participants	5 participants

SECONDARY outcome

Timeframe: Baseline and up to 27 months from the first dose of Cycle 1 (Study Day 1), and before Cycle 2 treatment

Population: ITT Population. Only those participants who received Cycle 1 treatment (including the Redosing Cycle) were assessed.

IgM is a basic antibody that is produced by B cells. It is the first antibody to appear in response to initial exposure to antigen. IgM flare is defined as an IgM level that increases by \>25% from baseline (BL) and is associated with a response to treatment. Avoidance of IgM flare indicates the lack of an increase in IgM of \>25% from BL.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With IgM Flare for Cycle 1 Response (Including the Redosing Cycle) >25% increase from BL, any response, n=15, 22	7 participants	9 participants
Number of Participants With IgM Flare for Cycle 1 Response (Including the Redosing Cycle) =<25% increase from BL, any response, n=15, 22	8 participants	13 participants
Number of Participants With IgM Flare for Cycle 1 Response (Including the Redosing Cycle) >25% increase from BL, PR/MR response , n=7, 15	1 participants	2 participants
Number of Participants With IgM Flare for Cycle 1 Response (Including the Redosing Cycle) =<25% increase from BL, PR/MR response , n=7, 15	6 participants	13 participants

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: ITT Population. Only those participants classified as responders were included in the analysis. Participants who had disease progression or death were counted as events, and other participants were censored at the date of the last adequate assessment in the study.

Duration of response is defined as the time from the initial response to relapse/disease progression (DP) or death. DP for CR is defined as the reappearance of the IgM protein, new signs/symptoms attributable to WM, evidence of active disease or recurrence of bone marrow involvement by lymphoplasmacytic cells, or the appearance of any new lymph node \>=1.5 centimeters on any axis. Progression for PR/MR is either a \>=25% increase in IgM from the lowest attained response value or progression of lymphadenopathy, organomegaly, cytopenias, or other clinically significant signs/symptoms caused by WM.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=5 events Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=9 events Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Duration of Response for All Responders (CR, PR, MR), as Assessed by the Investigator	449.0 days Interval 275.0 to There were too few events (disease progression or death) to estimate the third quartile.	455.0 days Interval 337.0 to 1016.0

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: ITT Population. Participants who experienced disease progression or death were counted as events, and other participants were censored at the time of the last adequate assessment in the study.

Time to disease progression is defined as the time from baseline to disease progression or death.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=8 events Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=13 events Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Progression-free Survival	558.0 days Interval 353.0 to 666.0	536.0 days Interval 414.0 to 1093.0

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: ITT Population. Only participants classified as responders (CR, PR, and MR) were assessed.

Time to response is defined as the time from baseline to the first response date.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=7 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=15 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Time to Response for Responders	78 days Interval 72.0 to 269.0	81 days Interval 78.0 to 104.0

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: ITT Population. Only those participants who died during the study and during the follow-up period were assessed.

Overall survival is defined as the time from baseline until death due to any cause.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: From the first dose (Cycle 1 Day 1) up to 6 months after the end of the last cycle of treatment; blood collected on each dosing day, weekly up to Week 8, and every 4 weeks up to Week 24/Month 7

Population: Pharmacokinetic (PK) Population: all participants from whom a PK sample was obtained and analyzed. Data were provided for the number of participants for whom the parameter could be determined.

Clearance (CL) is defined as the volume of plasma that is cleared of drug per unit of time. Blood samples for the quantification of ofatumumab were collected during each cycle and for up to 6 months after the end of each cycle.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=21 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Clearance of Ofatumumab	27.9 milliliters/hour (ml/hr) Interval 16.0 to 48.6	13.5 milliliters/hour (ml/hr) Interval 8.7 to 20.8

SECONDARY outcome

Population: PK Population. Data were provided for the number of participants for whom the parameter could be determined.

Volume of distribution at steady state (Vss) is defined as the apparent volume of distribution of the drug in the body at steady state. Blood samples for the quantification of ofatumumab were collected during each cycle and for up to 6 months after the end of each cycle.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=21 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Volume of Distribution at Steady State of Ofatumumab	10.0 Liters (L) Interval 8.9 to 11.2	10.7 Liters (L) Interval 9.6 to 12.0

SECONDARY outcome

Population: PK Population. Data were provided for the number of participants for whom the parameter could be determined.

Half-life (t½) is defined as the time required for the concentration of the drug in plasma to decrease to one-half of its current value. Blood samples for the quantification of ofatumumab were collected during each cycle and for up to 6 months after the end of each cycle.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=21 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Half-life of Ofatumumab	10.9 Days (d) Interval 6.8 to 17.5	23.9 Days (d) Interval 16.2 to 35.2

SECONDARY outcome

Population: PK Population. Data were provided for the number of participants attending each visit for whom the parameter could be determined.

Cmax is defined as the maximum observed drug concentration after administration, and Ctrough is defined as the drug concentration observed prior to the start of the next dose. Blood samples for the quantification of ofatumumab were collected during each cycle and for up to 6 months after the end of each cycle.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=21 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Cmax and Ctrough of Ofatumumab Cmax, Course 1 Dose 1, n=14,19	68.3 micrograms/milliliter (µg/ml) Interval 48.0 to 97.1	72.1 micrograms/milliliter (µg/ml) Interval 57.4 to 90.6
Cmax and Ctrough of Ofatumumab Cmax, Course 1 Dose 3, n=0,19	NA micrograms/milliliter (µg/ml) No participants were analyzed at the indicated time point; therefore, the mean and the CI could not be calculated.	465 micrograms/milliliter (µg/ml) Interval 386.0 to 561.0
Cmax and Ctrough of Ofatumumab Cmax, Course 1 Dose 4, n=13,0	259 micrograms/milliliter (µg/ml) Interval 195.0 to 344.0	NA micrograms/milliliter (µg/ml) No participants were analyzed at the indicated time point; therefore, the mean and the CI could not be calculated.
Cmax and Ctrough of Ofatumumab Cmax, Course 1 Dose 5, n=0,18	NA micrograms/milliliter (µg/ml) No participants were analyzed at the indicated time point; therefore, the mean and the CI could not be calculated.	640 micrograms/milliliter (µg/ml) Interval 523.0 to 783.0
Cmax and Ctrough of Ofatumumab Ctrough, Course 1 Dose 2, n=7,12	3.0 micrograms/milliliter (µg/ml) Interval 0.3 to 27.4	8.0 micrograms/milliliter (µg/ml) Interval 2.0 to 32.2
Cmax and Ctrough of Ofatumumab Ctrough, Course 1 Dose 3, n=11,19	13.9 micrograms/milliliter (µg/ml) Interval 2.1 to 91.3	121 micrograms/milliliter (µg/ml) Interval 67.3 to 217.0
Cmax and Ctrough of Ofatumumab Ctrough, Course 1 Dose 4, n=13,21	23.4 micrograms/milliliter (µg/ml) Interval 4.3 to 128.0	181 micrograms/milliliter (µg/ml) Interval 95.3 to 344.0
Cmax and Ctrough of Ofatumumab Ctrough, Course 1 Dose 5, n=0,18	NA micrograms/milliliter (µg/ml) No participants were analyzed at the indicated time point; therefore, the mean and the CI could not be calculated.	249 micrograms/milliliter (µg/ml) Interval 127.0 to 489.0
Cmax and Ctrough of Ofatumumab Cmax, Course 2 Dose 1, n=9,11	53.2 micrograms/milliliter (µg/ml) Interval 33.1 to 85.6	64.8 micrograms/milliliter (µg/ml) Interval 42.8 to 98.2
Cmax and Ctrough of Ofatumumab Cmax, Course 2 Dose 3, n=8,12	554 micrograms/milliliter (µg/ml) Interval 420.0 to 730.0	577 micrograms/milliliter (µg/ml) Interval 436.0 to 762.0
Cmax and Ctrough of Ofatumumab Cmax, Course 2 Dose 5, n=10,12	528 micrograms/milliliter (µg/ml) Interval 339.0 to 825.0	803 micrograms/milliliter (µg/ml) Interval 616.0 to 1046.0
Cmax and Ctrough of Ofatumumab Ctrough, Course 2 Dose 2, n=7,10	8.1 micrograms/milliliter (µg/ml) Interval 1.2 to 52.7	20.4 micrograms/milliliter (µg/ml) Interval 4.7 to 89.2
Cmax and Ctrough of Ofatumumab Ctrough, Course 2 Dose 3, n=8,12	144 micrograms/milliliter (µg/ml) Interval 64.6 to 319.0	169 micrograms/milliliter (µg/ml) Interval 102.0 to 280.0
Cmax and Ctrough of Ofatumumab Ctrough, Course 2 Dose 4, n=11,12	225 micrograms/milliliter (µg/ml) Interval 110.0 to 458.0	310 micrograms/milliliter (µg/ml) Interval 200.0 to 482.0
Cmax and Ctrough of Ofatumumab Ctrough, Course 2 Dose 5, n=11,12	279 micrograms/milliliter (µg/ml) Interval 155.0 to 503.0	384 micrograms/milliliter (µg/ml) Interval 273.0 to 542.0

SECONDARY outcome

Population: PK Population. Data were provided for the number of participants attending each visit for whom the parameter could be calculated..

AUC(0-tau) is the area under the drug concentration-time curve over the dosing interval (one week). AUC(0-inf) is the area under the drug concentration-time curve from time zero extrapolated to infinite time. Blood samples for the quantification of ofatumumab were collected during each cycle and for up to 6 months after the end of each cycle.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=21 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
AUC(0-tau) and AUC(0-inf) of Ofatumumab AUC(0-tau), Course 1 Dose 5, n=0,18	NA micrograms X hours/milliliters (µg.h/mL) No participants were analyzed at the indicated time point; therefore, the mean and the CI could not be calculated.	75526 micrograms X hours/milliliters (µg.h/mL) Interval 56462.0 to 101028.0
AUC(0-tau) and AUC(0-inf) of Ofatumumab AUC(0-inf), Course 1 Dose 4, n=9,0	120886 micrograms X hours/milliliters (µg.h/mL) Interval 53956.0 to 270842.0	NA micrograms X hours/milliliters (µg.h/mL) No participants were analyzed at the indicated time point; therefore, the mean and the CI could not be calculated.
AUC(0-tau) and AUC(0-inf) of Ofatumumab AUC(0-inf), Course 1 Dose 5, n=0,18	NA micrograms X hours/milliliters (µg.h/mL) No participants were analyzed at the indicated time point; therefore, the mean and the CI could not be calculated.	392012 micrograms X hours/milliliters (µg.h/mL) Interval 220019.0 to 698454.0
AUC(0-tau) and AUC(0-inf) of Ofatumumab AUC(0-tau), Course 2 Dose 5, n=10,12	61259 micrograms X hours/milliliters (µg.h/mL) Interval 36684.0 to 102296.0	106275 micrograms X hours/milliliters (µg.h/mL) Interval 82044.0 to 137663.0
AUC(0-tau) and AUC(0-inf) of Ofatumumab AUC(0-inf), Course 2 Dose 5, n=8,12	221675 micrograms X hours/milliliters (µg.h/mL) Interval 70622.0 to 695814.0	507794 micrograms X hours/milliliters (µg.h/mL) Interval 286020.0 to 901528.0
AUC(0-tau) and AUC(0-inf) of Ofatumumab AUC(0-tau), Course 1 Dose 4, n=13,0	21419 micrograms X hours/milliliters (µg.h/mL) Interval 11637.0 to 39424.0	NA micrograms X hours/milliliters (µg.h/mL) No participants were analyzed at the indicated time point; therefore, the mean and the CI could not be calculated.

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: Safety Population. Only those participants with post-ofatumumab HAHA results were analyzed.

All human-antihuman antibody (HAHA) samples were first tested in a screening assay to identify potential HAHA positives. Next, samples that tested positive in the screening assay were further tested in the confirmation assay to determine the specificity of the signal to ofatumumab. Confirmed positive samples were reported as positive.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=11 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=20 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With at Least One Confirmed Positive Post-ofatumumab HAHA Result	1 participants	4 participants

SECONDARY outcome

Timeframe: Baseline and Month 3

Population: ITT Population: only participants with blood count data at both Baseline and Month 3 were included in the analysis.

CD4+ and CD19+ are two key flow cytometry parameters, and total hemolytic complement (CD50) is a complement parameter. Change from Baseline was calculated as the post-Baseline value minus the Baseline value.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Change From Baseline in Blood Counts (CD4+, CD19+, CD50) at Month 3 After Treatment CD4+	-35.5 cells per microliter (µL) Interval -277.0 to 194.0	98 cells per microliter (µL) Interval -50.0 to 503.0
Change From Baseline in Blood Counts (CD4+, CD19+, CD50) at Month 3 After Treatment CD19+	-26 cells per microliter (µL) Interval -734.0 to 0.0	-24.5 cells per microliter (µL) Interval -61.0 to -9.0
Change From Baseline in Blood Counts (CD4+, CD19+, CD50) at Month 3 After Treatment CD50	9 cells per microliter (µL) Interval -122.0 to 104.0	-43 cells per microliter (µL) Interval -287.0 to 50.0

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: Safety Population. Only those participants who experienced an SAE categorized as being related to study drug were assessed.

An SAE is any event occurring at any dose that results in any of the following: death, a life-threatening adverse drug experience (ADE; at immediate risk of death from the experience as it occurred), inpatient hospitalization/prolongation of existing hospitalization, a persistent/significant disability/incapacity, or a congenital anomaly/birth defect. Medical events that may not result in death, be life threatening, or require hospitalization may be considered to be a serious ADEs when based upon appropriate medical judgment. Relatedness was based on the Investigator's medical judgement.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=2 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=2 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With the Indicated SAEs Related to Study Drug Haemolysis	0 participants	1 participants
Number of Participants With the Indicated SAEs Related to Study Drug Chest pain	0 participants	1 participants
Number of Participants With the Indicated SAEs Related to Study Drug Cryoglobulinaemia	1 participants	0 participants
Number of Participants With the Indicated SAEs Related to Study Drug Fluid overload	0 participants	1 participants
Number of Participants With the Indicated SAEs Related to Study Drug Renal failure acute	1 participants	0 participants
Number of Participants With the Indicated SAEs Related to Study Drug Pulmonary oedema	0 participants	1 participants

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: Safety Population. Only those participants who experienced a study drug-related AE were assessed.

An AE is any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. The Investigator assessed whether the AE was possibly or probably related to study drug.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=13 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Lymph node pain	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Neutropenia	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Ear pruritus	3 participants	2 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Eye pruritus	3 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Ocular hyperaemia	1 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Abnormal sensation in eye	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Eye swelling	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Decreased appetite	2 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Fluid overload	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Hypophagia	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Increased appetite	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Headache	1 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Paraesthesia	0 participants	2 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Sinus headache	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Infusion related reaction	2 participants	3 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Blood creatinine increased	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Body temperature increased	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Protein total increased	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Hypersensitivity	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Serum sickness	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Rhinitis	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Urinary tract infection	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Bradycardia	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Insomnia	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Renal failure acute	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Thirst	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Vomiting	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Cryoglobulinaemia	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Pallor	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Arthralgia	1 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Fluid retention	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Hypoaesthesia	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Psychomotor hyperactivity	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Weight decreased	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Pruritus	4 participants	8 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Urticaria	4 participants	9 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Rash	4 participants	3 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Pruritus generalised	2 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Hyperhidrosis	1 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Erythema	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Palmar erythema	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Rash macular	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Swelling face	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Throat irritation	7 participants	3 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Nasal congestion	1 participants	2 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Oropharyngeal pain	0 participants	3 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Dyspnoea	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Epistaxis	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Painful respiration	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Pulmonary oedema	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Rhinitis allergic	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Rhinorrhoea	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Sneezing	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Pyrexia	2 participants	5 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Chills	1 participants	5 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Chest pain	1 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Chest discomfort	2 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Fatigue	1 participants	2 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Non-cardiac chest pain	2 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Asthenia	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Ill-defined disorder	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Local swelling	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Malaise	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Pain	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Abdominal pain	2 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Diarrhoea	0 participants	3 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Nausea	0 participants	2 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Paraesthesia oral	0 participants	2 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Abdominal discomfort	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Dyspepsia	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Hypoaesthesia oral	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Lip swelling	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Oral pain	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Oral pruritus	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Stomatitis	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Flushing	6 participants	4 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Hypotension	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Back pain	1 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Limb discomfort	0 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Muscle spasms	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Musculoskeletal pain	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Myalgia	0 participants	2 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Trismus	1 participants	0 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Anaemia	0 participants	2 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Haemolysis	1 participants	1 participants
Number of Participants With the Indicated SAEs and Non-serious AEs Related to Study Drug Leukopenia	0 participants	1 participants

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: Safety Population. Only those participants who experienced an AE leading to their withdrawal from the study were assessed.

Certain AEs led to permanent discontinuation of study drug and hence resulted in their withdrawal from the study.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=2 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=1 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With the Indicated AEs Leading to Permanent Discontinuation of Study Drug and Withdrawal From Study Haemolysis	1 participants	1 participants
Number of Participants With the Indicated AEs Leading to Permanent Discontinuation of Study Drug and Withdrawal From Study Febrile neutropenia	1 participants	0 participants
Number of Participants With the Indicated AEs Leading to Permanent Discontinuation of Study Drug and Withdrawal From Study Myocardial ischaemia	0 participants	1 participants
Number of Participants With the Indicated AEs Leading to Permanent Discontinuation of Study Drug and Withdrawal From Study Fluid overload	0 participants	1 participants
Number of Participants With the Indicated AEs Leading to Permanent Discontinuation of Study Drug and Withdrawal From Study Renal failure acute	1 participants	0 participants
Number of Participants With the Indicated AEs Leading to Permanent Discontinuation of Study Drug and Withdrawal From Study Pulmonary oedema	0 participants	1 participants
Number of Participants With the Indicated AEs Leading to Permanent Discontinuation of Study Drug and Withdrawal From Study Haemolytic anaemia	0 participants	1 participants

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: Safety Population. Only those participants who experienced a \>=Grade 3 AE were assessed.

AEs were graded using the Common Toxicity Criteria for AEs from the Cancer Therapy Evaluation Program, Division of Cancer Therapy, National Cancer Institute. Grades: 0 = No AE or within normal limits; 1 = Mild AE; 2 = Moderate AE; 3 = Severe and undesirable AE; 4 = Life-threatening or disabling AE; 5 = Death related to AE.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=8 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=8 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With the Indicated >=Grade 3 AEs Haemolysis	1 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Anaemia	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Febrile neutropenia	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Haemolytic anaemia	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Chest pain	1 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Chest discomfort	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Dyspnoea exertional	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Epistaxis	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Pulmonary oedema	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Cryoglobulinaemia	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Serum sickness	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Dizziness	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Headache	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Syncope	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Myocardial ischaemia	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Abdominal discomfort	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Urinary tract infection	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Fluid overload	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Back pain	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Renal failure acute	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Rash	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Neutropenia	1 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Fatigue	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Small intestinal obstruction	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Pyrexia	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Blood creatinine increased	1 participants	0 participants
Number of Participants With the Indicated >=Grade 3 AEs Haemoglobin decreased	0 participants	1 participants
Number of Participants With the Indicated >=Grade 3 AEs Protein total increased	0 participants	1 participants

SECONDARY outcome

Timeframe: From baseline up to approximately 5 years

Population: Safety Population. Only those participants who experienced \>=Grade 3 infusion-related AEs were assessed.

Infusion-related AEs are the AEs that resulted from administration of study drug through infusion. AEs were graded using the Common Toxicity Criteria for AEs from the Cancer Therapy Evaluation Program, Division of Cancer Therapy, National Cancer Institute. Grades: 0 = No AE or within normal limits; 1 = Mild AE; 2 = Moderate AE; 3 = Severe and undesirable AE; 4 = Life-threatening or disabling AE; 5 = Death related to AE.

Outcome measures

Outcome measures
Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=2 Participants Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=2 Participants Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
Number of Participants With the Indicated Infusion-related >=Grade 3 AE Chest pain	1 participants	1 participants
Number of Participants With the Indicated Infusion-related >=Grade 3 AE Chest discomfort	1 participants	0 participants
Number of Participants With the Indicated Infusion-related >=Grade 3 AE Back pain	0 participants	1 participants
Number of Participants With the Indicated Infusion-related >=Grade 3 AE Rash	1 participants	0 participants

Adverse Events

300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5

Serious events: 5 serious events

Other events: 15 other events

Deaths: 0 deaths

300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5

Serious events: 7 serious events

Other events: 20 other events

Deaths: 0 deaths

Serious adverse events

Other adverse events

Additional Information

GSK Response Center

GlaxoSmithKline

Phone: 866-435-7343

Results disclosure agreements

Principal investigator is a sponsor employee GSK agreements may vary with individual investigators, but will not prohibit any investigator from publishing. GSK supports the publication of results from all centers of a multi-center trial but requests that reports based on single-site data not precede the primary publication of the entire clinical trial.
Publication restrictions are in place

Restriction type: OTHER

Measure	300 mg Ofatumumab, Wk. 1; 1000/2000 mg Ofatumumab, Wk. 2-4/2-5 n=15 participants at risk Participants received ofatumumab intravenously (IV) in Cycle 1 (defined as a treatment period of up to 4 weeks \[Weeks (Wk.) 1 through 4\]) (300 milligrams \[mg\] at Week 1 and 1000 mg at Weeks 2 through 4) and were followed up for 11 weeks (Weeks 5-16). After Week 16, during the Redosing Cycle (RC), participants who had Minor Response or stable disease after Cycle 1 and had not received another Waldenstrom's Macroglobulinemia (WM) therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response in either Cycle 1 or the RC and subsequently progressed before 36 months entered Cycle 2 of treatment and received IV ofatumumab 300 mg at Week 1 and IV ofatumumab 2000 mg during Weeks 2 through 5.	300 mg Ofatumumab, Wk. 1; 2000 mg Ofatumumab, Wk. 2-5 n=22 participants at risk Participants received ofatumumab IV at 300 mg at Week 1 and 2000 mg at Weeks 2 through 5 in Cycle 1 (defined as a treatment period of up to 5 weeks \[Weeks 1 through 5\]) and were followed up for 10 weeks (Weeks 6-16). After Week 16, during the RC, participants who had Minor Response or stable disease after Cycle 1 and had not received another WM therapy received 300 mg IV ofatumumab at Week 1 and 2000 mg IV ofatumumab at Weeks 2 through 5. Participants who achieved a response and subsequently progressed before 36 months entered Cycle 2 of treatment and received 300 mg at Week 1 and 2000 mg during Weeks 2 through 5.
General disorders Catheter site haemorrhage	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
General disorders Chest pain	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
General disorders Fatigue	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
General disorders Pyrexia	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	9.1% 2/22 • Participants were followed from baseline up to approximately 5 years.
Blood and lymphatic system disorders Haemolysis	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Blood and lymphatic system disorders Anaemia	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
Blood and lymphatic system disorders Febrile neutropenia	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
Respiratory, thoracic and mediastinal disorders Dyspnoea exertional	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Respiratory, thoracic and mediastinal disorders Epistaxis	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
Respiratory, thoracic and mediastinal disorders Pleural effusion	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Respiratory, thoracic and mediastinal disorders Pulmonary oedema	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Cardiac disorders Cardiac failure	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Cardiac disorders Myocardial ischaemia	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Gastrointestinal disorders Gingival bleeding	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
Immune system disorders Cryoglobulinaemia	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
Infections and infestations Bacteraemia	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Injury, poisoning and procedural complications Hip fracture	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
Metabolism and nutrition disorders Fluid overload	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Nervous system disorders Syncope	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
Renal and urinary disorders Renal failure acute	6.7% 1/15 • Participants were followed from baseline up to approximately 5 years.	0.00% 0/22 • Participants were followed from baseline up to approximately 5 years.
Blood and lymphatic system disorders Haemolytic anaemia	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.
Gastrointestinal disorders Small intestinal obstruction	0.00% 0/15 • Participants were followed from baseline up to approximately 5 years.	4.5% 1/22 • Participants were followed from baseline up to approximately 5 years.