Frontline Rituximab-Bendamustine Followed by Rituximab Maintenance Demonstrates Improved PFS vs R-CHOP Therapy Among Patients With Follicular Lymphoma

First-line rituximab-bendamustine followed by rituximab maintenance therapy for patients with previously untreated advanced stage follicular lymphoma (FL) resulted in significantly longer progression-free survival (PFS) than rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) followed by rituximab maintenance therapy, according to a retrospective, multicenter, observational study.

“Although [rituximab-bendamustine] has demonstrated excellent efficacy in this setting, the role of rituximab as maintenance therapy after this combination must be clarified, since some studies have indicated that maintenance therapy after bendamustine could increase the risk of toxicity, especially infectious toxicity,” explained Mariana Bastos-Oreiro, MD, PhD, Hospital General Universitario Gregorio Marañón, Madrid, Spain, and colleagues.

Investigators analyzed 405 patients with FL from 17 GELTAMO centers who received rituximab-based regimens followed by rituximab maintenance therapy for untreated advanced stage FL. In this study, 245 patients were treated with R-CHOP and 160 patients with rituximab-bendamustine. The R-CHOP-treated group included younger patients, with a shorter time from biopsy to start of treatment. Study authors noted that grade 3a tumor was more frequently represented in this group, as well as were higher-risk patients, while the median age in the rituximab-bendamustine group was higher. Both groups received the maintenance therapy with comparable proportions, which was 97% in each cohort. However, 8 patients in the R-CHOP cohort and 5 patients in the rituximab-bendamustine cohort (comprising 3% of both cohorts) could not initiate maintenance therapy, which was due to early progression (82%), while 18% were related to toxicity from the frontline regimen.

Results demonstrated that the complete response (CR) rate at the end of the induction period was higher with rituximab-bendamustine, and relapses were more frequent with R-CHOP. The transformation rate was similar in both groups, as was early progression (progression of disease ≤24 months [POD24]) and death. Succeeding a median follow-up of 81 months (95% confidence interval [CI], 77 to 86) (68 (60 to 75) for rituximab-bendamustine and 96 (88 to 103) for R-CHOP), 6-year PFS (95% CI) was 71% (66 to 76) and 6-year overall survival (OS) (95% CI) was 91% (88 to 94). Additionally, the 6-year rate of PFS was 79% (95% CI, 72 to 86) for rituximab-bendamustine vs. 67% (95% CI, 61 to 73) for R-CHOP (P = 0.046) and 6-year OS was 91% (95% CI, 86 to 96) for rituximab-bendamustine vs. 91% (95% CI, 87 to 94) for R-CHOP (P = 0.49).

Safety measurements detailed that during induction, prophylaxis against pneumocystis was more frequently used in the R-CHOP group and anti-herpes in the rituximab-bendamustine group. It was noted that discontinuation due to toxicity was more frequent in the rituximab-bendamustine group and due to disease progression in the R-CHOP group. Furthermore, severe neutropenia and infections were also more frequent in the rituximab-bendamustine group.

Bastos-Oreiro and colleagues concluded that “the results of this multicenter study show that the use of [rituximab]-bendamustine followed by rituximab maintenance in patients with previously untreated follicular lymphoma resulted in significantly longer PFS compared to patients treated with R-CHOP.”

“The frequency of high-grade adverse events was higher with this regimen during maintenance regarding neutropenia and infectious toxicity, conferring more significant therapy discontinuation in this group, without impact in mortality. Older patients also benefit from this regimen without further toxicity,” they added.

Source:

Bastos-Oreiro M, Gutierrez A, Cabero A, et al. Comparing R-bendamustine vs. R-CHOP plus maintenance therapy as first-line systemic treatment in follicular lymphoma: A multicenter retrospective GELTAMO study. Cancers. 2024; 16(7):1285. doi:10.339016071285