Accelerated approval to Polivy (Polatuzumab vedotin), in combination with the chemotherapy bendamustine and rituximab (P-BR) by the U.S. FDA for the treatment of patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL), indicates the unmet need and necessity of newer therapies for the treatment of this aggressive disease despite the availability of CAR-T cell therapies.
Approval of Polivy was based on complete response (CR) rate and duration of response (DOR) in a open-label clinical trial (Study GO29365). The study randomized 80 patients with relapsed or refractory DLBCL after at least one prior therapy to either P+ BR (N = 40) or BR alone (N = 40) for six cycles. At the end of treatment, the CR rate was 40% with P-BR compared to 18% with BR alone. Of the 25 patients who achieved a partial or complete response to P-BR, 16 (64%) had a DOR of at least six months and 12 (48%) had a DOR of at least 12 months.
Reviewer acknowledged that the magnitude of the treatment effect with the addition of Polatuzumab is uncertain because of the small sample size. However, the observed differences between arms in depth of response at end of therapy, ORR, and DoR were clinically meaningful. These response data provided substantial evidence of effectiveness and were the basis for the recommended accelerated approval, though the PFS and OS data were not sufficiently robust to support a regular approval. At the same time, the recommended indication has been restricted to patients with relapsed or refractory DLBCL after at least two prior therapies due to the paucity of data in patients with one prior therapy. Thus, Polivy became the first chemoimmunotherapy regimen approved by the US FDA for patients with relapsed or refractory DLBCL.