Frontline treatment with patients in the BRIGHT study.
The bendamustine-rituximab (BR) regimen had superior 5-year progression-free survival rates, event-free survival, and duration of response, compared with either rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) or rituximab with cyclophosphamide, vincristine, and prednisone (R-CVP). The follow-up study did not find a significant difference in overall survival, however.
While the cumulative evidence from BRIGHT and other studies supports BR as a first-line treatment option for patients with indolent non-Hodgkin lymphoma (iNHL) and mantle cell lymphoma (MCL), the lack of an overall survival benefit indicates that the sequence of BR and R-CHOP or R-CVP “may not be critical,” Ian W. Flinn, MD, PhD, of Sarah Cannon Research Institute in Nashville, and his colleagues wrote in the Journal of Clinical Oncology.
“[The] choice of regimen for the initial treatment of iNHL may be driven more by patient preferences regarding the differences in toxicity profile,” the researchers wrote.
Initial results from the BRIGHT study found that BR was noninferior to R-CHOP/R-CVP in terms of complete response rate (P = .0225 for noninferiority). The present study includes outcomes data for at least 5 years after completion of the study treatment.
For the entire study, the median follow-up was 65.0 months for patients in the BR group and 64.1 months for patients in the R-CHOP/R-CVP group. Overall, the intention-to-treat population included 224 patients receiving BR and 223 patients receiving R-CHOP and R-CVP.
The median time to progression was not reached in either treatment group. The 5-year progression-free survival (PFS) rates were 65.5% in the BR group and 55.8% in the R-CHOP/R-CVP group. The difference between these rates was significant, with a hazard ratio of 0.61 (95% confidence interval, 0.45-0.85; P = .0025).
Similarly, event-free survival was better in the BR group versus the R-CHOP/R-CVP group (HR, 0.63; 95% CI, 0.46-0.84; P = .0020). Duration of response also favored the BR treatment regimen (HR, 0.66; 95% CI, 0.47-0.92; P = .0134).
The long-term follow-up showed no significant difference in overall survival, with an HR of 1.15 for BR versus R-CHOP/R-CVP (95% CI, 0.72-1.84; P = .5461). Overall, there were 40 deaths in the BR treatment group and 32 deaths in the R-CHOP/R-CVP group.
Whether patients received maintenance rituximab did not affect the overall survival between groups. Similarly, there was no difference in overall survival by lymphoma type.
“Benefit from BR treatment did not translate to prolonged [overall survival], possibly because of the subsequent lines of therapy, including the use of BR in patients in the R-CHOP/R-CVP group,” the researchers wrote.
In terms of safety, the follow-up data showed no significant difference in early non–disease-related mortality between the treatment groups. However, the BRIGHT study showed higher rates of secondary malignancies in the BR group, compared with R-CHOP/R-CVP. That finding was not seen in the Study Group of Indolent Lymphomas Non-Hodgkin Lymphoma (StiL NHL) 1 trial, and the authors could not provide an explanation for the increase in their research.
This study was supported by Teva Pharmaceuticals. Dr. Flinn reported receiving institutional research funding from Teva and receiving institutional research funding from or serving as a consultant to several other companies.
SOURCE: Flinn IW et al. J Clin Oncol. 2019 Feb 27. doi: 10.1200/JCO.18.00605.