Background: BRIGHT, a phase 3, open-label, noninferiority study comparing efficacy and safety of bendamustine plus rituximab (BR) vs rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) or rituximab with cyclophosphamide, vincristine and prednisone (R-CVP) in treatment-naive patients (pts) with indolent non-Hodgkin lymphoma (iNHL) or mantle cell lymphoma (MCL), showed that the complete response rate for first-line BR was statistically noninferior to R-CHOP/R-CVP (Blood 2014). Pts were monitored for ≥5 years (yr) to assess the overall effect of BR or R-CHOP/R-CVP in a controlled clinical setting. This analysis reports the time-to-event variables of the 5-yr follow-up (FU) study. Methods: Pts with iNHL or MCL randomized to 6-8 cycles of BR or R-CHOP/R-CVP underwent complete assessments at end of treatment, then were monitored regularly. Progression-free survival (PFS), event-free survival (EFS), duration of response (DOR) and overall survival (OS) were compared using a stratified log-rank test. Results: Of 447 randomized pts, 224 received BR, 104 R-CHOP, and 119 R-CVP; 419 entered the FU. The median FU time was 65.0 and 64.1 months for BR and R-CHOP/R-CVP, respectively. The 5-yr PFS rate was 65.5% (95% CI 58.5-71.6) and 55.8% (48.4-62.5), and OS was 81.7% (75.7-86.3) and 85% (79.3-89.3) for BR and R-CHOP/R-CVP, respectively. The hazard ratio (95% CI) for PFS was 0.61 (0.45-0.85; P= .0025), EFS 0.63 (0.46-0.84; P= .0020), DOR 0.66 (0.47-0.92; P= .0134), and OS 1.15 (0.72-1.84; P= .5461) comparing BR vs R-CHOP/R-CVP. Similar results were found in iNHL [PFS 0.70 (0.49-1.01; P= .0582)] and MCL [PFS 0.40 (0.21-0.75; P= .0035)], with the strongest effect in MCL. Use of R maintenance was similar, 43% in BR and 45% in R-CHOP/R-CVP. B was included as second-line in 27 (36%) of the 75 pts requiring therapy who originally received R-CHOP/R-CVP. Comparable safety profiles with expected adverse events were observed in the FU study in BR vs R-CHOP/R-CVP. Conclusions: The long-term FU of the BRIGHT study has confirmed that PFS, EFS, and DOR were significantly better for BR, and OS was not statistically different between BR and R-CHOP/R-CVP. The safety profile was as previously reported. Clinical trial information: NCT00877006