Obinutuzumab Immunochemotherapy Yielded Sustained Improvement in Progression-Free Survival vs Rituximab Among Patients With FL

Final Results from the Phase 3 GALLIUM Trial

Final analysis from the phase 3 GALLIUM trial showed a sustained improvement in progression-free survival (PFS) with obinutuzumab-based immunochemotherapy compared to rituximab-based immunochemotherapy among patients with previously untreated follicular lymphoma (FL).

According to William Townsend, MD, University College Hospitals London, United Kingdom, “Although rituximab-based immunochemotherapy has significantly improved outcomes for patients with previously untreated FL, most patients experience relapse and shorter durations of remission with subsequent lines of treatment.” 

The GALLIUM trial compared the efficacy and safety of obinutuzumab-based immunochemotherapy with rituximab-based immunochemotherapy among patients with previously untreated FL or marginal zone lymphoma (MZL). The primary end point was progression-free survival, and secondary end points included overall survival, time to next anti-lymphoma treatment, event-free survival, and safety. 

A total of 1202 patients with previously untreated FL were enrolled and randomized on a 1-to-1 basis to receive either obinutuzumab-based immunochemotherapy (n = 601) or rituximab-based immunochemotherapy (n = 601). Subsequently, maintenance therapy with the same antibody was continued for up to 2 years. The final analysis was conducted after a median follow-up duration of 7.9 years, ranging from 0 to 9.8 years. 

The 7-year PFS rate for patients receiving obinutuzumab-based immunochemotherapy was 63.4% compared to 55.7% of those receiving rituximab-based immunochemotherapy (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.64 to 0.93; P = .006). Additionally, 74.1% of those in the obinutuzumab group had not yet started their next anti-lymphoma treatment at 7 years, compared with 65.4% in the rituximab group (HR, 0.71; 95% CI, 0.58 to 0.87; P = .001). Overall survival was similar across groups, but those patients who achieved a complete molecular response experienced significantly higher PFS and overall survival. 

Serious adverse events were observed in 48.9% of patients in the obinutuzumab group versus 43.4% of patients in the rituximab group. In the follow-up phase, the most common grade ≥3 adverse events of particular interest were neutropenia (3.5% vs 1.7%) and infections (8.7% vs 5.8%). There was no significant difference in the rate of fatal adverse events, and no new safety signals were noted. 

Dr Townsend and coauthors concluded, “These data demonstrate the long-term benefit of obinutuzumab-based immunochemotherapy and confirm its role as a standard-of-care for the first-line treatment of advanced-stage FL, taking into account patient characteristics and safety considerations.” 

Source: 

Townsend, W, Hiddemann W, Buske C, et al. Obinutuzumab versus rituximab immunochemotherapy in previously untreated iNHL: Final results from the GALLIUM study. HemaSphere 7(7):p e919, Published online July 2023. doi: 10.1097/HS9.0000000000000919