Adding Obinutuzumab to Bendamustine Clinically Beneficial for Patients With Rituximab-refractory NHL

Obinutuzumab plus bendamustine followed by obinutuzumab maintenance significantly improved progression-free survival, compared with bendamustine monotherapy, in rituximab-refractory patients with indolent non-Hodgkin lymphoma, a study published in the journal The Lancet Oncology has shown.¹

For this international, open-label, phase 3 GADOLIN trial, investigators enrolled 396 adult patients with histologically documented, CD20-positive indolent non-Hodgkin lymphoma refractory to rituximab. Participants were randomly assigned 1:1 to receive obinutuzumab 1000 mg IV on days 1, 8, and 15 during cycle 1 and on day 1 during cycles 2 to 6 plus bendamustine 90 mg/m² IV on days 1 and 2 during cycles 1 to 6, or bendamustine monotherapy 120 mg/m² IV on days 1 and 2 for 6, 28-day cycles. Patients in the obinutuzumab group without disease progression after induction then received obinutuzumab maintenance at a dose of 1000 mg IV every 2 months for up to 2 years.

After a median follow-up time of 21.9 months in the obinutuzumab group and 20.3 months in the bendamustine monotherapy group, median progression-free survival had not yet been reached (95% CI, 22.5-not estimable) with obinutuzumab and bendamustine, compared with 14.9 months (95% CI, 12.8-16.6) with bendamustine monotherapy (hazard ratio, 0.55; 95% CI, 0.40-0.74; P = .0001).

Grade 3 to 5 adverse events were reported in 68% of immunotherapy-treated patients, versus 62% in those treated with single-agent bendamustine. Treatment-related adverse events led to death in 3 patients in the combination arm and 5 patients in the bendamustine monotherapy group.

The findings suggest that obinutuzumab plus bendamustine followed by obinutuzumab maintenance is a new treatment option for patients with indolent non-Hodgkin lymphoma who have relapsed after or are no longer responding to rituximab-based treatment.

Reference

1. Sehn LH, Chua N, Mayer J, Dueck G, Trněný M, Bouabdallah K, et al. Obinutuzumab plus bendamustine versus bendamustine monotherapy in patients with rituximab-refractory indolent non-Hodgkin lymphoma (GADOLIN): a randomised, controlled, open-label, multicentre, phase 3 trial [published online ahead of print June 23, 2016]. Lancet Oncol. doi: 10.1016/S1470-2045(16)30097-3.