Background: The BRIGHT study demonstrated that first-line BR was non-inferior to R-CHOP/R-CVP in terms of complete remission rate in indolent NHL and MCL. This is the first detailed analysis of the safety and tolerability of the study regimens. Methods: Patients were preselected for R-CHOP or R-CVP, and then randomized to 6-8 cycles of BR (28-d cycle) or the preselected standard regimen (21-d cycles). BR dosing was bendamustine 90 mg/m²/d as a 30-min infusion on days 1 and 2 plus rituximab 375 mg/m²given before bendamustine on day 1. Colony stimulating factors (CSFs) and antiemetics were given per local standards. Results: In patients preselected for R-CHOP, 103 received BR and 98 R-CHOP. In patients preselected for R-CVP, 118 received BR and 116 R-CVP. For all regimens, ≥ 88% of patients received the planned 6 cycles. Main differences in adverse events (AEs), all grades, are shown in the Table. Incidence of grade 3/4 AEs was 69% for R-CHOP vs 56% BR, and 50% for R-CVP vs 56% BR. Grade 3/4 drug hypersensitivity, neuropathy, and rash were infrequent. Antiemetic use was similar between groups except use of aprepitant as an adjunct to 5-HT3 antagonists was higher with R-CHOP (23% [19% in cycle 1]) than BR (9% [2%]) or R-CVP (3% [2%]). CSF use was higher with R-CHOP (61%) than BR (29%) or R-CVP (27%). Analyses of event prevalence over the treatment period and by region will also be presented. Conclusions: BR, R-CHOP, and R-CVP have significantly distinct AE profiles. More nausea, vomiting, and hypersensitivity occurred with BR while more constipation, neuropathy, and alopecia occurred with RECHOP/R-CVP. Support: Teva BPP R&D, Inc. Clinical trial information: NCT00877006.

^a From multiple preferred terms. * P <0.05; ^† P <0.005.