On June 10, 2019, the FDA accelerated the approval of polatuzumab vedotin-piiq (Polivy; Genentech), a CD79b-directed antibody-drug conjugate, in combination with bendamustine (Bendeka, Treanda) plus rituximab (Rituxan or a biosimilar; BR) for the treatment of patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) who have received ≥2 previous therapies.
The FDA approval of polatuzumab was based on results from the phase 1b/2 GO29365 clinical trial that included 80 patients with relapsed or refractory DLBCL who had received ≥1 previous treatment regimens. Patients were randomized in a 1:1 ratio to polatuzumab plus BR or BR alone for six 21-day cycles. The efficacy of the polatuzumab-based combination regimen was based on complete response rate and duration of response, which was defined as the time the disease remained in remission.
Results showed a complete response rate of 40% in patients treated with polatuzumab plus BR versus 18% in those treated with BR alone. Of the 25 patients who achieved a partial or complete response with polatuzumab plus BR, 16 (64%) had a duration of response of ≥6 months and 12 (48%) had a duration of response of ≥12 months.
The most common (≥20%) adverse effects associated with polatuzumab plus BR were neutropenia, thrombocytopenia, anemia, peripheral neuropathy, fatigue, diarrhea, pyrexia, decreased appetite, and pneumonia.
“Antibody-drug conjugates are an emerging class of targeted immunotherapies for cancer. This type of therapy, unlike traditional chemotherapy, is intended to target specific cells,” said Richard Pazdur, MD, Director, FDA’s Oncology Center of Excellence. “Today’s approval of Polivy provides an alternative option for patients in whom multiple treatments have not worked.”