Trial Outcomes & Findings for Efficacy and Safety Study of Lenalidomide Plus R-CHOP Chemotherapy Versus Placebo Plus R-CHOP Chemotherapy in Untreated ABC Type Diffuse Large B-cell Lymphoma (NCT NCT02285062)

NCT ID: NCT02285062

Last Updated: 2023-06-22

Results Overview

Progression free survival was defined as the time (months) from the date of randomization to the date of disease progression or death (any cause), whichever occurred earlier and was assessed by the Independent Response Adjudication Committee (IRAC). Relapse from complete response (CR) was considered as disease progression throughout the study. Disease progression was determined based on the Revised Response Criteria for Malignant Lymphoma. The PFS analysis was based on the censoring rules using the Food and Drug Administration (FDA) Guidance. Participants who did not experience disease progression and who did not die before the clinical data cutoff date were censored at the date of last adequate response assessment.

• Recruitment status: COMPLETED
• Study phase: PHASE3
• Target enrollment: 570 participants
• Primary outcome timeframe: From the date of randomization up to the data cut off date of 15 March 2019; median follow-up of 24.5 months
• Results posted on: 2023-06-22

Participant Flow

Intent to Treat (ITT) population - all randomized participants. Safety population - all participants that received at least 1 dose of study medication.

Participant milestones

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Pre-Treatment Period STARTED	285	285
Pre-Treatment Period COMPLETED	284	283
Pre-Treatment Period NOT COMPLETED	1	2
Treatment Period STARTED	283	284
Treatment Period COMPLETED	211	240
Treatment Period NOT COMPLETED	72	44

Reasons for withdrawal

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Pre-Treatment Period Protocol Violation	0	2
Pre-Treatment Period Participant withdrew consent	1	0

Baseline Characteristics

One creatinine clearance value is missing.

Baseline characteristics by cohort

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Total n=570 Participants Total of all reporting groups
Age, Continuous	62.5 Years STANDARD_DEVIATION 11.72 • n=285 Participants	63.9 Years STANDARD_DEVIATION 9.35 • n=285 Participants	63.2 Years STANDARD_DEVIATION 10.62 • n=570 Participants
Age, Customized < 65	138 Participants n=285 Participants	137 Participants n=285 Participants	275 Participants n=570 Participants
Age, Customized ≥ 65	147 Participants n=285 Participants	148 Participants n=285 Participants	295 Participants n=570 Participants
Sex: Female, Male Female	121 Participants n=285 Participants	142 Participants n=285 Participants	263 Participants n=570 Participants
Sex: Female, Male Male	164 Participants n=285 Participants	143 Participants n=285 Participants	307 Participants n=570 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	14 Participants n=285 Participants	17 Participants n=285 Participants	31 Participants n=570 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	270 Participants n=285 Participants	267 Participants n=285 Participants	537 Participants n=570 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=285 Participants	1 Participants n=285 Participants	2 Participants n=570 Participants
Race/Ethnicity, Customized White	173 Participants n=285 Participants	183 Participants n=285 Participants	356 Participants n=570 Participants
Race/Ethnicity, Customized Asian	101 Participants n=285 Participants	89 Participants n=285 Participants	190 Participants n=570 Participants
Race/Ethnicity, Customized Black or African American	2 Participants n=285 Participants	3 Participants n=285 Participants	5 Participants n=570 Participants
Race/Ethnicity, Customized Other	3 Participants n=285 Participants	2 Participants n=285 Participants	5 Participants n=570 Participants
Race/Ethnicity, Customized Not Collected or Reported	6 Participants n=285 Participants	8 Participants n=285 Participants	14 Participants n=570 Participants
Body Surface Area (BSA)	1.780 m^2 STANDARD_DEVIATION 0.2167 • n=285 Participants	1.775 m^2 STANDARD_DEVIATION 0.2101 • n=285 Participants	1.777 m^2 STANDARD_DEVIATION 0.2132 • n=570 Participants
Eastern Cooperative Oncology Group (ECOG) Performance Status 0 = Fully Active	129 Participants n=285 Participants	111 Participants n=285 Participants	240 Participants n=570 Participants
Eastern Cooperative Oncology Group (ECOG) Performance Status 1 = Restrictive but ambulatory	104 Participants n=285 Participants	118 Participants n=285 Participants	222 Participants n=570 Participants
Eastern Cooperative Oncology Group (ECOG) Performance Status 2 = Ambulatory but unable to work	52 Participants n=285 Participants	56 Participants n=285 Participants	108 Participants n=570 Participants
Creatinine Clearance	92.08 mL/min STANDARD_DEVIATION 35.576 • n=285 Participants • One creatinine clearance value is missing.	90.19 mL/min STANDARD_DEVIATION 31.040 • n=284 Participants • One creatinine clearance value is missing.	91.14 mL/min STANDARD_DEVIATION 33.373 • n=569 Participants • One creatinine clearance value is missing.
International Prognostic Index (IPI) Score = 2	121 Participants n=285 Participants	120 Participants n=285 Participants	241 Participants n=570 Participants
International Prognostic Index (IPI) Score ≥ 3	164 Participants n=285 Participants	165 Participants n=285 Participants	329 Participants n=570 Participants
Presence of Bulky Disease < 7.0 cm (Non-Bulky Disease)	188 Participants n=285 Participants	186 Participants n=285 Participants	374 Participants n=570 Participants
Presence of Bulky Disease ≥ 7.0 cm (Bulky Disease)	97 Participants n=285 Participants	99 Participants n=285 Participants	196 Participants n=570 Participants
Disease Stage of Diffuse Large B-Cell Lymphoma at Diagnosis Stage I	0 Participants n=285 Participants	1 Participants n=285 Participants	1 Participants n=570 Participants
Disease Stage of Diffuse Large B-Cell Lymphoma at Diagnosis Stage II	37 Participants n=285 Participants	32 Participants n=285 Participants	69 Participants n=570 Participants
Disease Stage of Diffuse Large B-Cell Lymphoma at Diagnosis Stage III	80 Participants n=285 Participants	98 Participants n=285 Participants	178 Participants n=570 Participants
Disease Stage of Diffuse Large B-Cell Lymphoma at Diagnosis Stage IV	168 Participants n=285 Participants	154 Participants n=285 Participants	322 Participants n=570 Participants

PRIMARY outcome

Timeframe: From the date of randomization up to the data cut off date of 15 March 2019; median follow-up of 24.5 months

Population: The Intent-to-treat (ITT) population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not.

Progression free survival was defined as the time (months) from the date of randomization to the date of disease progression or death (any cause), whichever occurred earlier and was assessed by the Independent Response Adjudication Committee (IRAC). Relapse from complete response (CR) was considered as disease progression throughout the study. Disease progression was determined based on the Revised Response Criteria for Malignant Lymphoma. The PFS analysis was based on the censoring rules using the Food and Drug Administration (FDA) Guidance. Participants who did not experience disease progression and who did not die before the clinical data cutoff date were censored at the date of last adequate response assessment.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Kaplan-Meier Estimate of Progression Free Survival (PFS)	NA months Median PFS and the upper and lower 95% confidence interval was not reached due to the low number of events.	NA months Interval 35.5 to Median PFS and the upper and lower 95% confidence interval was not reached due to the low number of events.

SECONDARY outcome

Timeframe: From the date of randomization up to the data cut off date of 15 March 2019; median follow-up was 24.5 months

Population: The ITT population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not.

EFS was defined as the time (months) from randomization until occurrence of one of the following events, whichever occurred first: • Disease progression • Initiation of subsequent systemic anti-lymphoma therapy • Death due to any cause The assessment of EFS was conducted by the IRAC using the International Working Group (IWG) criteria for NHL. Pre-specified optional therapies such as the extra 2 doses of single agent rituximab after Cycle 6 or consolidation radiotherapy did not count as an EFS event (initiation of subsequent systemic anti-lymphoma therapy) if the decision to treat and the location to be treated was determined prior to randomization. Participants who did not experience any of the events defined in the categories above before the clinical data cutoff date were censored at date last known alive.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Kaplan-Meier (K-M) Estimate of Event Free Survival (EFS)	NA Months Median EFS was not reached due to the low number of events.	NA Months Interval 31.3 to Median EFS was not reached due to the low number of events.

SECONDARY outcome

Timeframe: From randomization until death due to any cause (up to approximately 86 months)

Population: The ITT population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not.

Overall survival was assessed by the Independent Response Adjudication Committee (IRAC) and defined as time from randomization until death due to any cause. Participants who withdrew consent were censored at the time of withdrawal. Participants who were still alive before the clinical data cutoff date and participants who were lost to follow-up were censored at date last known alive.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
K-M Estimate of Overall Survival (OS)	NA Months Median OS and the upper and lower 95% confidence interval were not reached due to the low number of events.	NA Months Median OS and the upper and lower 95% confidence interval were not reached due to the low number of events.

SECONDARY outcome

Timeframe: From randomization date up to the data cut off date of 15 March 2019; median follow-up was 24.5 months

Population: The ITT population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not. Participants who had a CR.

The percentage of participants who achieved a CR after initiation of the study treatment and prior to initiation of subsequent systemic antilymphoma therapy as assessed by the IRAC. A CR = complete metabolic response; target nodes/nodal masses regressed on computed tomography to (≤ 1.5 cm in their greatest transverse diameter for nodes > 1.5 cm prior to therapy. Regressed to normal size by imaging, and absence of nodules related to lymphoma. If bone marrow was involved prior to therapy, no evidence of fluorodeoxyglucose avid disease in marrow per International Working Group (IWG) 2014 for Non-Hodgkin's Lymphoma (NHL). Participants who did not have any adequate response assessments during this period were not considered as responders.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Percentage of Participants Who Achieved a Complete Response (CR)	69.1 Percentage of Participants Interval 63.4 to 74.4	64.9 Percentage of Participants Interval 59.1 to 70.4

SECONDARY outcome

Timeframe: From randomization date up to the data cut off date of 15 March 2019; median total treatment duration was 18.10 weeks for both treatment arms; range = 1.6 to 29.0 weeks for R2-CHOP arm and 0.3 to 22.9 weeks for placebo-R-CHOP arm

Population: The Intent-to-treat population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not. Participants who had a PR or better.

An objective response = percentage of participants who achieved a complete response or partial response after initiation of the treatment and prior to initiation of subsequent systemic anti-lymphoma therapy. A CR = complete metabolic response; Target nodes/nodal masses regressed on computed tomography to (≤ 1.5 cm in their greatest transverse diameter for nodes > 1.5 cm prior to therapy. Regressed to normal size by imaging, and absence of nodules related to lymphoma. If bone marrow was involved prior to therapy, no evidence of fluorodeoxyglucose avid disease in marrow. PR = ≥ 50% decrease in sum of the product of the diameters (SPD) of up to 6 of the largest dominant nodes or nodal masses. No increase in other nodes, liver, or spleen. Splenic nodules regressed by ≥ 50% in their SPD or for single nodules, in the greatest transverse diameter; no new lesions. Participants who did not have any adequate response assessments during this period were not considered as responders.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Percentage of Participants Who Achieved an Objective Response	90.9 Percentage of Participants Interval 86.9 to 94.0	90.9 Percentage of Participants Interval 86.9 to 94.0

SECONDARY outcome

Timeframe: From randomization date up to the data cut off date of 15 March 2019; median follow-up was 24.5 months.

Population: The ITT population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not. Participants who had a response.

Duration of complete response was calculated for complete responders only and was defined as the time from documented initial complete response prior to initiation of subsequent systemic antilymphoma therapy until documented disease progression or death, whichever occurred earlier. Participants who had not progressed or died at the time of the analysis were censored at the date of last response assessment demonstrating no disease progression. Participants who changed treatment without evidence of disease progression were censored at the last assessment showing no progression prior to treatment change.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=197 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=185 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
K-M Estimate of Duration of Complete Response	NA Months Median duration of CR could not be estimated due to the low number of events.	NA Months Median duration of CR could not be estimated due to due to the low number of events.

SECONDARY outcome

Timeframe: From randomization date up to the data cut off date of 15 March 2019; median follow-up was 24.5 months

Population: The Intent-to-treat (ITT) population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not.

Time to next lymphoma therapy was defined as the time from randomization to the time of treatment change for the next lymphoma treatment. Participants without treatment change were censored at date last known alive. Pre-specified optional therapies such as the extra 2 doses of single agent rituximab after Cycle 6 or consolidation radiotherapy did not count as treatment change for the next lymphoma therapy if the decision to treat and the location to be treated were determined prior to randomization.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
K-M Estimate of Time to Next Lymphoma Therapy (TTNLT)	NA Months Median time to next lymphoma treatment was not reached due to low number of events.	NA Months Median time to next lymphoma treatment was not reached due to low number of events.

SECONDARY outcome

Timeframe: Screening, Midcycle = after Cycle 3 but before Cycle 4, Cycle 6 Day 1 (C6D1), End of Treatment (C6,D21), and Follow-Up Period up to Week 34

Population: The ITT population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not.

The completion rate for FACT-Lym assessments was judged by looking at the number of completed FACT-Lym assessments at each time point. The FACT-Lym was considered completed if at least 1 calculable score was present. Completion rates were calculated as the number and percentage of participants out of the total number of patients in the ITT population and summarized by visit/cycle and treatment group. The FACT-Lym is a health related quality of life (HRQoL) questionnaire targeted to the management of chronic illness, predominantly within oncology and is considered an extension of the FACT-General questionnaire.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Percentage of Participants Who Completed the Functional Assessment of Cancer Therapy Lymphoma (FACT-Lym) Questionnaire Screening	98.6 Percentage of Participants	98.2 Percentage of Participants
Percentage of Participants Who Completed the Functional Assessment of Cancer Therapy Lymphoma (FACT-Lym) Questionnaire Midcycle = After Cycle 3, but before Cycle 4	87.0 Percentage of Participants	86.3 Percentage of Participants
Percentage of Participants Who Completed the Functional Assessment of Cancer Therapy Lymphoma (FACT-Lym) Questionnaire End of Treatment (EoT) = 3-4 weeks after C6	76.1 Percentage of Participants	79.6 Percentage of Participants
Percentage of Participants Who Completed the Functional Assessment of Cancer Therapy Lymphoma (FACT-Lym) Questionnaire Follow-Up Period: Week 34	67.7 Percentage of Participants	69.5 Percentage of Participants

SECONDARY outcome

Timeframe: Screening, Midcycle = after Cycle 3 but before Cycle 4, Cycle 6 Day 1 (C6D1), End of Treatment (C6,D21), and Follow-Up Period up to Week 34

Population: The ITT population was defined as all participants who were randomized into the trial, regardless of whether they received study treatment or not.

The completion rate for EQ-5D assessments was judged by looking at the number of completed assessments at each time point. Completion rates were calculated as the number and percentage of participants out of the total number of patients in the ITT population and summarized by visit/cycle and treatment group. The EQ-5D-3L is a generic, self-reported preference-based measure of health across five dimensions: mobility, self-care, pain, usual activities, and anxiety/depression. Each dimension has three levels of 'severity' corresponding to "no problems", "some problems" and "extreme problems". The instrument is scored using the United Kingdom (UK) index ranges from -0.594 - 1, where 0 equates to death and 1 equates to full health -0.594 is considered 'worse than death'.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=285 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=285 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Percentage of Participants Who Completed the Euroqol 5-Dimension 3-Level (EQ-5D-3L) Health Related Quality of Life (HR-QoL) Questionnaire Screening	98.9 Percentage of Participants	97.9 Percentage of Participants
Percentage of Participants Who Completed the Euroqol 5-Dimension 3-Level (EQ-5D-3L) Health Related Quality of Life (HR-QoL) Questionnaire Midcycle	87.0 Percentage of Participants	86.3 Percentage of Participants
Percentage of Participants Who Completed the Euroqol 5-Dimension 3-Level (EQ-5D-3L) Health Related Quality of Life (HR-QoL) Questionnaire End of Treatment (EoT)	76.5 Percentage of Participants	79.6 Percentage of Participants
Percentage of Participants Who Completed the Euroqol 5-Dimension 3-Level (EQ-5D-3L) Health Related Quality of Life (HR-QoL) Questionnaire Follow-Up Period: Week 34	68.1 Percentage of Participants	69.1 Percentage of Participants

SECONDARY outcome

Timeframe: Baseline and Midcycle = after Cycle 3 but before Cycle 4, Cycle 6 Day 1 (C6D1), End of Treatment (C6,D21), and Follow-Up Period up to Week 34

Population: The HRQoL evaluable population was defined as all participants in the ITT population who had: at least one baseline and the corresponding post-baseline calculable FACT-Lym score assessment; where post-baseline is any subsequent time excluding unscheduled visits (i.e. at Midcycle, C6D1, EOT or a follow-up visit).

The FACT-Lym questionnaire is a validated instrument for assessing the impact of lymphoma on HRQL and contains 42 questions covering HRQL and common lymphoma symptoms and treatment side-effects. It begins with the Functional Assessment of Cancer Therapy - General (FACT-G), which contains 27 questions covering four core subscales: Physical Wellbeing (7 items), Social/Family Wellbeing (7), Emotional Wellbeing (6), and Functional Wellbeing (7). The FACT-Lym also includes an Additional Concerns subscale (15 questions) used to assess NHL-related symptoms and concerns. All questions are answered on a 5-point scale ranging from "not at all" (0) to "very much" (4). The physical well-being subscale ranges from 0 to 28, where higher scores reflect better HRQoL.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=257 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=257 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Mean Change From Baseline in the FACT-Lym Physical Well-Being Subscale Midcycle	-0.7 Units on a Scale Standard Deviation 5.91	0.2 Units on a Scale Standard Deviation 5.40
Mean Change From Baseline in the FACT-Lym Physical Well-Being Subscale C6 D1	-0.0 Units on a Scale Standard Deviation 6.35	0.9 Units on a Scale Standard Deviation 6.02
Mean Change From Baseline in the FACT-Lym Physical Well-Being Subscale EoT = 3-4 weeks after C6	1.5 Units on a Scale Standard Deviation 5.53	0.7 Units on a Scale Standard Deviation 5.72
Mean Change From Baseline in the FACT-Lym Physical Well-Being Subscale Follow-Up Period: Week 34	2.8 Units on a Scale Standard Deviation 5.24	2.6 Units on a Scale Standard Deviation 5.55

SECONDARY outcome

Timeframe: Baseline and Midcycle = after Cycle 3 but before Cycle 4, Cycle 6 Day 1 (C6D1), End of Treatment (C6,D21), and Follow-Up Period up to Week 34

Population: The HRQoL evaluable population was defined as all participants in the ITT population who had: at least one baseline and the corresponding post-baseline calculable FACT-Lym score assessment; where post-baseline is any subsequent time excluding unscheduled visits (i.e. at Midcycle, C6D1, EOT or a follow-up visit).

The FACT-Lym questionnaire is a validated instrument for assessing the impact of lymphoma on HRQL and contains 42 questions covering HRQL and common lymphoma symptoms and treatment side-effects. It begins with the Functional Assessment of Cancer Therapy - General (FACT-G), which contains 27 questions covering four core subscales: Physical Wellbeing (7 items), Social/Family Wellbeing (7), Emotional Wellbeing (6), and Functional Wellbeing (7). The FACT-Lym also includes an Additional Concerns subscale (15 questions) used to assess NHL-related symptoms such as pain, itching, night sweats,trouble sleeping, fatigue and trouble concentrating and concerns regarding lumps and swelling, fevers, infections, weight, appetite, emotional stability and treatment. All questions are answered on a 5-point scale ranging from "not at all" (0) to "very much" (4). The Additional Concerns subscale ranges from 0 to 60, where higher scores reflect better HRQoL.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=257 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=255 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Mean Change From Baseline in the FACT-Lym Additional Concerns Subscale Midcycle	3.8 Units on a Scale Standard Deviation 10.33	4.1 Units on a Scale Standard Deviation 8.88
Mean Change From Baseline in the FACT-Lym Additional Concerns Subscale EoT = 3-4 weeks after C6	6.6 Units on a Scale Standard Deviation 10.11	4.5 Units on a Scale Standard Deviation 9.62
Mean Change From Baseline in the FACT-Lym Additional Concerns Subscale Follow-Up Period: Week 34	8.3 Units on a Scale Standard Deviation 10.61	6.5 Units on a Scale Standard Deviation 9.20
Mean Change From Baseline in the FACT-Lym Additional Concerns Subscale C6 D1	5.8 Units on a Scale Standard Deviation 11.11	5.2 Units on a Scale Standard Deviation 9.40

SECONDARY outcome

Timeframe: Baseline and Midcycle = after Cycle 3 but before Cycle 4, Cycle 6 Day 1 (C6D1), End of Treatment (C6,D21), and Follow-Up Period up to Week 34

Population: The HRQoL evaluable population was defined as all participants in the ITT population who had: at least one baseline and the corresponding post-baseline calculable FACT-Lym score assessment; where post-baseline is any subsequent time excluding unscheduled visits (i.e. at Midcycle, C6D1, EOT or a follow-up visit).

The FACT-Lym questionnaire is a validated instrument for assessing the impact of lymphoma on HRQL and contains 42 questions covering HRQL and common lymphoma symptoms and treatment side-effects. It begins with the Functional Assessment of Cancer Therapy - General (FACT-G), which contains 27 questions covering four core subscales: Physical Wellbeing (7 items), Social/Family Wellbeing (7), Emotional Wellbeing (6), and Functional Wellbeing (7). The FACT-Lym also includes an Additional Concerns subscale (15 questions) used to assess NHL-related symptoms and concerns. All questions are answered on a 5-point scale ranging from "not at all" (0) to "very much" (4). The functional well-being subscale ranges from 0 to 28, where higher scores reflect better HRQoL.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=258 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=256 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Mean Change From Baseline in the FACT-Lym Functional Well-Being Subscale C6 D1	0.0 Units on a Scale Standard Deviation 6.24	1.4 Units on a Scale Standard Deviation 5.63
Mean Change From Baseline in the FACT-Lym Functional Well-Being Subscale EoT = 3-4 weeks after C6	1.0 Units on a Scale Standard Deviation 6.53	0.7 Units on a Scale Standard Deviation 6.71
Mean Change From Baseline in the FACT-Lym Functional Well-Being Subscale Follow-Up Period: Week 34	2.3 Units on a Scale Standard Deviation 6.65	3.1 Units on a Scale Standard Deviation 6.17
Mean Change From Baseline in the FACT-Lym Functional Well-Being Subscale Midcycle	-0.5 Units on a Scale Standard Deviation 6.12	0.5 Units on a Scale Standard Deviation 5.84

SECONDARY outcome

Timeframe: Baseline and Midcycle = after Cycle 3 but before Cycle 4, Cycle 6 Day 1 (C6D1), End of Treatment (C6,D21), and Follow-Up Period up to Week 34

Population: The HRQoL evaluable population was defined as all participants in the ITT population who had: at least one baseline and the corresponding post-baseline calculable FACT-Lym score assessment; where post-baseline is any subsequent time excluding unscheduled visits (i.e. at Midcycle, C6D1, EOT or a follow-up visit).

The FACT-Lym questionnaire is a validated instrument for assessing the impact of lymphoma on HRQL and contains 42 questions covering HRQL and common lymphoma symptoms and treatment side-effects. It begins with the Functional Assessment of Cancer Therapy - General (FACT-G), which contains 27 questions covering four core subscales: Physical Wellbeing (7 items), Social/Family Wellbeing (7), Emotional Wellbeing (6), and Functional Wellbeing (7). The FACT-Lym also includes an Additional Concerns subscale (15 questions) used to assess NHL-related symptoms and concerns. All questions are answered on a 5-point scale ranging from "not at all" (0) to "very much" (4). The FACT-Lym TOI is calculated by summing the Physical Well-being, Functional Well-being and Additional Concerns scores and has a range of 0 to 116. Higher scores reflect better HRQoL or fewer symptoms.

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=256 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=254 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Mean Change From Baseline in the FACT-Lym Trial Outcome Index (TOI) Midcycle	2.6 Units on a Scale Standard Deviation 18.26	4.6 Units on a Scale Standard Deviation 16.49
Mean Change From Baseline in the FACT-Lym Trial Outcome Index (TOI) C6 D1	5.9 Units on a Scale Standard Deviation 19.85	7.5 Units on a Scale Standard Deviation 17.40
Mean Change From Baseline in the FACT-Lym Trial Outcome Index (TOI) EoT = 3-4 weeks after C6	9.1 Units on a Scale Standard Deviation 18.51	5.8 Units on a Scale Standard Deviation 18.64
Mean Change From Baseline in the FACT-Lym Trial Outcome Index (TOI) Follow-Up Period: Week 34	13.5 Units on a Scale Standard Deviation 18.74	12.2 Units on a Scale Standard Deviation 17.97

SECONDARY outcome

Timeframe: Baseline and Midcycle = after Cycle 3 but before Cycle 4, Cycle 6 Day 1 (C6D1), End of Treatment (C6,D21), and Follow-Up Period up to Week 34

Population: The HRQoL evaluable population was defined as all participants in the ITT population who had: at least one baseline and the corresponding post-baseline calculable EQ-5D score assessment; where post-baseline is any subsequent time excluding unscheduled visits (i.e. at Midcycle, C6D1, EOT or a follow-up visit).

The EQ-5D-3L is a generic, self-reported preference-based measure of health across five dimensions: mobility, self-care, pain, usual activities, and anxiety/depression. Each dimension has three levels of 'severity' corresponding to "no problems", "some problems" and "extreme problems". The instrument is scored as a single summary index using one of the available EQ-5D-3L value sets; in this study the UK scoring weights 9 were used. The UK index ranges from -0.594 to 1, where 0 equates to death and 1 equates to full health (-0.594 is considered 'worse than death').

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=257 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=255 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Mean Change From Baseline in the Euroqol 5-Dimension 3-Level (EQ-5D-3L) Index Score Midcycle	0.08 Units on a Scale Standard Deviation 0.308	0.08 Units on a Scale Standard Deviation 0.281
Mean Change From Baseline in the Euroqol 5-Dimension 3-Level (EQ-5D-3L) Index Score C6 D1	0.10 Units on a Scale Standard Deviation 0.325	0.14 Units on a Scale Standard Deviation 0.330
Mean Change From Baseline in the Euroqol 5-Dimension 3-Level (EQ-5D-3L) Index Score EoT = 3-4 weeks after C6	0.10 Units on a Scale Standard Deviation 0.309	0.06 Units on a Scale Standard Deviation 0.319
Mean Change From Baseline in the Euroqol 5-Dimension 3-Level (EQ-5D-3L) Index Score Follow-Up Period: Week 34	0.15 Units on a Scale Standard Deviation 0.293	0.09 Units on a Scale Standard Deviation 0.311

SECONDARY outcome

Timeframe: Baseline and Midcycle = after Cycle 3 but before Cycle 4, Cycle 6 Day 1 (C6D1), End of Treatment (C6,D21), and Follow-Up Period up to Week 34

Population: The HRQoL evaluable population was defined as all participants in the ITT population who had: at least one baseline and the corresponding post-baseline calculable EQ-5D score assessment; where post-baseline is any subsequent time excluding unscheduled visits (i.e. at Midcycle, C6D1, EOT or a follow-up visit).

The EQ-5D-3L questionnaire includes a visual analogue scale which records the respondent's self-rated health on a vertical, 0-100 scale where 100 = "Best imaginable health state" and 0 = "Worst imaginable health state". Higher scores again indicate better HRQoL and positive change scores indicate that post screening values were higher than those observed at screening. The EQ-5D-3L is a generic, self-reported preference-based measure of health across five dimensions: mobility, self-care, pain, usual activities, and anxiety/depression. Each dimension has three levels of 'severity' corresponding to "no problems", "some problems" and "extreme problems".

Outcome measures

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=256 Participants Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=255 Participants Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Mean Change From Baseline in the EQ-5D-3L Visual Analogue Scale (VAS) EoT = 3-4 weeks after C6	8.0 Units on a Scale Standard Deviation 18.7	6.0 Units on a Scale Standard Deviation 21.5
Mean Change From Baseline in the EQ-5D-3L Visual Analogue Scale (VAS) Follow-Up Period: Week 34	12.0 Units on a Scale Standard Deviation 20.2	9 Units on a Scale Standard Deviation 21.4
Mean Change From Baseline in the EQ-5D-3L Visual Analogue Scale (VAS) Midcycle	4.0 Units on a Scale Standard Deviation 20.5	3.0 Units on a Scale Standard Deviation 18.2
Mean Change From Baseline in the EQ-5D-3L Visual Analogue Scale (VAS) C6 D1	6.0 Units on a Scale Standard Deviation 23.5	9.0 Units on a Scale Standard Deviation 24.5

Adverse Events

Lenalidomide Plus R-CHOP (R2-CHOP)

Serious events: 104 serious events

Other events: 272 other events

Deaths: 85 deaths

Placebo Plus R-CHOP

Serious events: 88 serious events

Other events: 270 other events

Deaths: 88 deaths

Serious adverse events

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=283 participants at risk Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=284 participants at risk Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Blood and lymphatic system disorders Agranulocytosis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Anaemia	2.1% 6/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	2.1% 6/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Cytopenia	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Febrile neutropenia	11.0% 31/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	4.9% 14/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Leukopenia	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Lymphadenopathy	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Neutropenia	6.7% 19/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	4.6% 13/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Splenic necrosis	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Thrombocytopenia	5.7% 16/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Acute coronary syndrome	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Acute myocardial infarction	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Arrhythmia supraventricular	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Atrial fibrillation	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	1.4% 4/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Atrial flutter	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Cardiac arrest	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Cardiac disorder	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Cardiac failure	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	1.1% 3/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Cardiac failure congestive	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Coronary artery disease	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Cardiac disorders Sinus tachycardia	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Abdominal distension	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Abdominal pain	1.4% 4/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Dental caries	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Diarrhoea	2.1% 6/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	1.4% 4/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Diverticular perforation	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Enterocutaneous fistula	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Flatulence	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Gastric haemorrhage	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Gastroduodenal haemorrhage	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Gastrointestinal haemorrhage	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Haematochezia	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Intestinal obstruction	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Large intestine perforation	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Nausea	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Neutropenic colitis	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Stomatitis	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Vomiting	1.1% 3/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Asthenia	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Death	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Extravasation	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Face oedema	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders General physical health deterioration	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Hypothermia	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Malaise	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Non-cardiac chest pain	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Oedema peripheral	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Pyrexia	2.5% 7/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	3.2% 9/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Sudden cardiac death	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Hepatobiliary disorders Bile duct stone	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Hepatobiliary disorders Drug-induced liver injury	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Hepatobiliary disorders Hepatic function abnormal	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Hepatobiliary disorders Hepatitis	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Hepatobiliary disorders Jaundice cholestatic	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Hepatobiliary disorders Liver injury	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Immune system disorders Contrast media allergy	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Abdominal infection	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Anal abscess	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Appendicitis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Arthritis bacterial	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Bacterial infection	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Bronchitis	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Campylobacter gastroenteritis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Cellulitis	1.1% 3/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Clostridium difficile colitis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Cytomegalovirus infection	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Device related infection	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Device related sepsis	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Escherichia sepsis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Escherichia urinary tract infection	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Groin abscess	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Hepatitis B	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Herpes zoster	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Influenza	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Klebsiella infection	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Lower respiratory tract infection	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Lower respiratory tract infection bacterial	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Neutropenic sepsis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Osteomyelitis	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Parainfluenzae virus infection	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Pharyngitis	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Pneumocystis jirovecii pneumonia	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Pneumonia	5.3% 15/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	3.2% 9/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Pneumonia cytomegaloviral	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Pulmonary sepsis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Salmonellosis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Sepsis	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Septic shock	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Soft tissue infection	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Tracheobronchitis	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Upper respiratory tract infection	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Urinary tract infection	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	1.4% 4/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Varicella	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Craniofacial fracture	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Femur fracture	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Infusion related reaction	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	1.1% 3/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Lower limb fracture	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Lumbar vertebral fracture	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Procedural headache	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Procedural nausea	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Procedural vomiting	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Spinal compression fracture	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Spinal fracture	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Traumatic intracranial haemorrhage	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations Neutrophil count decreased	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations Platelet count decreased	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations White blood cell count decreased	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Dehydration	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Electrolyte imbalance	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Hypercalcaemia	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Hyperglycaemia	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Hypokalaemia	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Hyponatraemia	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Tumour lysis syndrome	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Musculoskeletal and connective tissue disorders Back pain	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Bladder transitional cell carcinoma	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Central nervous system lymphoma	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Diffuse large B-cell lymphoma	1.1% 3/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Lung adenocarcinoma	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Malignant melanoma in situ	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Tumour haemorrhage	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Altered state of consciousness	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Amnesia	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Aphasia	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Cerebrovascular accident	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Cognitive disorder	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Dizziness	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Dysarthria	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Epilepsy	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Guillain-Barre syndrome	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Haemorrhage intracranial	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Hemiparesis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Lethargy	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Memory impairment	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Nervous system disorder	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Neuralgia	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Presyncope	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Syncope	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Vocal cord paralysis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Psychiatric disorders Confusional state	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Psychiatric disorders Psychotic disorder	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Psychiatric disorders Tic	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Renal and urinary disorders Acute kidney injury	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Renal and urinary disorders Urinary retention	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Acute respiratory failure	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Cough	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Dyspnoea	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Interstitial lung disease	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	1.4% 4/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Pleural effusion	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Pleuritic pain	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Pneumonitis	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Pulmonary embolism	1.8% 5/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	1.1% 3/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Pulmonary oedema	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.70% 2/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Respiratory failure	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	1.1% 3/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Skin and subcutaneous tissue disorders Decubitus ulcer	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Skin and subcutaneous tissue disorders Drug eruption	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Skin and subcutaneous tissue disorders Rash	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Vascular disorders Deep vein thrombosis	0.71% 2/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Vascular disorders Hypertension	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Vascular disorders Hypotension	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Vascular disorders Jugular vein thrombosis	0.35% 1/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.00% 0/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Vascular disorders Thrombophlebitis superficial	0.00% 0/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	0.35% 1/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).

Other adverse events

Measure	Lenalidomide Plus R-CHOP (R2-CHOP) n=283 participants at risk Participants received lenalidomide 15 mg capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 cycles. Treatment continued until completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, whichever occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.	Placebo Plus R-CHOP n=284 participants at risk Participants received identically matching placebo capsules on days 1 to 14 of each 21 day treatment cycle followed by R-CHOP: rituximab 375 mg/m\^2 by intravenous (IV) administration on Day 1, doxorubicin 50 mg/m\^2 IV on Day 1, vincristine 1.4 mg/m\^2 IV on Day 1 (maximum dose of 2.0 mg total), cyclophosphamide 750 mg/m\^2 IV on Day 1 and oral or IV prednisone/prednisolone 100 mg on Day 1 to Day 5 of each 21 day treatment cycle for 6 to 8 cycles. Treatment continued until 6-8 cycles were completed, unless unacceptable toxicity, treatment change, disease progression, or withdrawal of consent, occurred first. An additional two doses (1 dose per 21-day cycle) of single agent rituximab after the 6 cycles of treatment were completed if considered standard of care per local practice.
Blood and lymphatic system disorders Anaemia	44.9% 127/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	33.5% 95/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Leukopenia	17.7% 50/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	17.6% 50/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Lymphopenia	12.4% 35/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	10.9% 31/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Neutropenia	64.7% 183/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	52.8% 150/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Blood and lymphatic system disorders Thrombocytopenia	24.0% 68/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	19.4% 55/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Abdominal pain	6.4% 18/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	5.6% 16/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Abdominal pain upper	3.9% 11/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	6.3% 18/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Constipation	32.5% 92/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	28.5% 81/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Diarrhoea	17.3% 49/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	14.1% 40/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Nausea	22.6% 64/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	23.2% 66/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Stomatitis	11.7% 33/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	13.0% 37/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Gastrointestinal disorders Vomiting	11.3% 32/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	9.2% 26/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Asthenia	13.8% 39/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	9.9% 28/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Fatigue	14.1% 40/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	17.6% 50/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Oedema peripheral	11.7% 33/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	11.3% 32/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
General disorders Pyrexia	18.4% 52/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	14.1% 40/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Infections and infestations Upper respiratory tract infection	8.1% 23/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	6.3% 18/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Injury, poisoning and procedural complications Infusion related reaction	9.5% 27/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	10.6% 30/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations Alanine aminotransferase increased	11.3% 32/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	9.5% 27/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations Aspartate aminotransferase increased	7.8% 22/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	7.0% 20/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations Lymphocyte count decreased	5.7% 16/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	4.2% 12/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations Platelet count decreased	7.4% 21/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	3.5% 10/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations Weight decreased	7.4% 21/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	3.5% 10/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Investigations White blood cell count decreased	12.4% 35/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	6.7% 19/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Decreased appetite	10.2% 29/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	11.3% 32/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Hyperglycaemia	6.4% 18/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	6.7% 19/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Metabolism and nutrition disorders Hypokalaemia	14.5% 41/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	9.9% 28/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Musculoskeletal and connective tissue disorders Arthralgia	6.4% 18/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	4.6% 13/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Musculoskeletal and connective tissue disorders Back pain	5.3% 15/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	7.7% 22/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Dizziness	5.7% 16/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	5.6% 16/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Dysgeusia	3.5% 10/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	5.3% 15/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Headache	9.2% 26/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	9.9% 28/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Neuropathy peripheral	6.7% 19/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	4.2% 12/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Paraesthesia	9.2% 26/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	9.5% 27/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Nervous system disorders Peripheral sensory neuropathy	18.0% 51/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	18.0% 51/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Psychiatric disorders Insomnia	8.1% 23/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	11.3% 32/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Cough	11.0% 31/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	7.0% 20/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Dyspnoea	3.9% 11/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	5.3% 15/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Respiratory, thoracic and mediastinal disorders Oropharyngeal pain	5.7% 16/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	3.5% 10/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).
Skin and subcutaneous tissue disorders Alopecia	17.0% 48/283 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).	15.1% 43/284 • Participants were assessed for All-Cause Mortality from the date of their randomization until study completion (assessed up to approximately 86 months). SAEs and Other AEs were monitored from the participant's first dose of study treatment up to 28 days after their last dose of LEN/PBO or any component of R-CHOP including the optional 2 additional doses of rituximab; measured up to approximately 33 weeks. The number at Risk for All-Cause Mortality represents all Randomized Participants (ITT Population). Serious Adverse Events and Other (Not Including Serious) Adverse Events represents all participants that received at least 1 dose of study medication (Safety Population).

Additional Information

Bristol-Myers Squibb Study Director

Bristol-Myers Squibb

Phone: Please email

Email: Clinical.Trials@bms.com

Results disclosure agreements

• Principal investigator is a sponsor employee Bristol-Myers Squibb Co. agreements with investigators vary; constant is our right to embargo communications regarding trial results prior to public release for a period ≤60 days from submittal for review. We will not prohibit investigators from publishing but will prohibit the disclosure of previously undisclosed confidential information other than study results, and request postponement of single-center publications until after disclosure of the clinical trial's primary publication.
• Publication restrictions are in place

Restriction type: OTHER