Obinutuzumab Receives Priority Review for Follicular Lymphoma

The U.S. Food and Drug Administration (FDA) granted priority review to the anti-CD20 monoclonal antibody obinutuzumab in combination with chemotherapy, followed by obinutuzumab alone, for the treatment of follicular lymphoma (FL).

The decision was based on results from the international, phase III GALLIUM study, which included 1,401 treatment-naïve patients with indolent non-Hodgkin lymphoma (NHL; 1,202 of whom had FL) who were randomized to receive frontline obinutuzumab (1,000 mg on days 1, 8, and 15 of cycle 1 and day 1 of subsequent cycles) plus chemotherapy (n=601) or rituximab (375 mg/m2 on day 1 of each cycle) plus chemotherapy (n=601). The chemotherapy regimen was either CHOP, CVP (cyclophosphamide, vincristine, prednisone), or bendamustine, depending on physician’s choice.

At median follow-up of 41.1 months (range not provided), the median PFS (primary endpoint) had not been reached in either treatment cohort. The risk of disease progression or death was reduced by 32 percent in patients treated with obinutuzumab, compared with rituximab (HR=0.68; 95% CI 0.54-0.837; p=0.0016). The HR for OS was 0.75 (95% CI 0.49-1.17; p=0.21).

At 34.5 months of follow-up (range not provided), the three-year PFS rate was 80 percent in the obinutuzumab cohort and 73.3 percent in the rituximab group, and the three-year OS rate was 94 percent and 92.1 percent, respectively. The ORR was 88.5 percent in the obinutuzumab group and 86.9 percent in the rituximab group. Rates of complete and partial remissions were similar between the obinutuzumab and rituximab groups (19.5% and 23.8%; 69.1% and 63.1%, respectively; p values not reported).

More patients in the obinutuzumab group achieved minimal residual disease negativity (92% vs. 84.9%; p=0.0041).

The most common grade 3-5 AEs that occurred more often in the obinutuzumab cohort were neutropenia (46.7% vs. 39.5%), infections (20.3% vs. 16.4%), IRRs (12.4% vs. 6.7%), thrombocytopenia (6.1% vs. 2.7%), second malignancies (4.7% vs. 2.7%), and cardiac events (3.9% vs. 2.8%).

The FDA’s decision is expected on or before December 23, 2017.

Obinutuzumab was previously approved for use in combination with bendamustine for patients with previously treated FL.

Source: Genentech press release, August 27, 2017.