Outcomes by Chemotherapy Backbone for Obinutuzumab vs Rituximab in Previously Untreated Follicular Lymphoma


Key Points

  • Obinutuzumab appeared to provide consistent benefit vs rituximab across the 3 chemotherapy backbones used in the trial.
  • Combination with CHOP was associated with higher rates of grade ≥ 3 toxicity. 

In an analysis of the GALLIUM trial reported in the Journal of Clinical Oncology, Hiddemann and colleagues found that obinutuzumab (Gazyva) appeared to provide consistent progression-free survival benefit vs rituximab (Rituxan) in previously untreated follicular lymphoma, irrespective of which chemotherapy backbone was used in the trial. Adverse event profiles differed according to chemotherapy backbones.

Study Details

In the trial, 1,202 patients were randomly assigned to receive obinutuzumab or rituximab along with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone), CVP (cyclophosphamide, vincristine, prednisone), or bendamustine, as nonrandomly assigned by study center. Responding patients received obinutuzumab or rituximab maintenance for 2 years or until disease progression. Baseline Follicular Lymphoma International Prognostic Index risk, bulky disease, and comorbidities differed among chemotherapy groups.

Overall, after a median follow-up of 41.1 months, the obinutuzumab group had a significantly improved 3-year progression-free survival vs the rituximab group (82% vs 75%, overall hazard ratio [HR] = 0.68, P = .0016). Progression-free survival at 3 years was 84% vs 76% among the 345 vs 341 patients receiving bendamustine (HR = 0.63, 95% confidence interval [CI] = 0.46–0.88), 81% vs 76% among 196 vs 203 patients receiving CHOP (HR = 0.72, 95% CI = 0.48–1.10), and 71% vs 64% among 60 vs 57 patients receiving CVP (HR = 0.79, 95% CI = 0.42–1.47).

Adverse Events

Overall, grade ≥ 3 adverse events occurred in 75% of the obinutuzumab group vs 69% of the rituximab group, with the most common being cytopenias (particularly neutropenia). Grade ≥ 3 adverse events (notably cytopenias) were most common with CHOP among chemotherapy regimens (89% and 74% in the obinutuzumab and rituximab groups). Grade ≥ 3 infections (26% and 20%) and second neoplasms (6% and 4%) were more common with bendamustine. Fatal events were also more frequent with bendamustine (6% and 5%), potentially reflecting differences in patient risk profiles.

The investigators concluded, “Improved [progression-free survival] was observed for [obinutuzumab] plus chemotherapy for all three chemotherapy backbones. Safety profiles differed, although comparisons are confounded by nonrandom chemotherapy allocation.”

The study was supported by F. Hoffmann-La Roche.

Wolfgang Hiddemann, MD, of University Hospital, LMU Munich, is the corresponding author for the Journal of Clinical Oncology article. 

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.