Obinutuzumab Maintenance in Follicular Lymphoma Is Associated With Better Progression Free Survival and Comparable Toxicity.

[BACKGROUND] The GALLIUM trial showed improved progression-free survival (PFS) with obinutuzumab (O)-based chemoimmunotherapy in first-line treatment of follicular lymphoma (FL), although with increased toxicity compared to rituximab (R). Our previous real-world study found similar toxicity between these protocols during induction.

[AIM] To compare real-world toxicity and outcomes of R versus O maintenance therapy in FL patients following first-line chemoimmunotherapy.

[METHODS] A multicenter retrospective study included FL patients treated with first-line R- or O-based chemoimmunotherapy. The primary outcome was any infection up to 6 months post-maintenance. Secondary outcomes included other toxicities, PFS, and overall survival (OS).

[RESULTS] We analyzed 134 patients (R: 71, O: 63). Baseline characteristics were similar except for higher diabetes and hypertension rates in the R group. The median number of maintenance cycles was comparable. Infections occurred in 56% of patients, with no significant difference (50.7% R vs. 61.9% O, p = 0.21). Grade   3 infections, febrile neutropenia, and treatment discontinuation rates were comparable between groups. Pneumonia and viral infections were less frequent with R versus O (13.8% vs. 28.1%, p = 0.019 and 19% vs. 39%, p = 0.004, respectively), while infusion reactions were higher (8.4% vs. 0%, p = 0.028). After 5.5 years, PFS favored O (19.7% vs. 4.8%, p = 0.028), with similar OS.

[CONCLUSIONS] In real-world settings, rituximab- and obinutuzumab-based chemoimmunotherapy with maintenance for FL exhibited a similar toxicity profile, with differences in specific infections. Obinutuzumab had superior PFS and similar OS compared with rituximab therapy, supporting obinutuzumab usage in first-line chemoimmunotherapy, especially in selected young and fit patients.