Polatuzumab Vedotin for Relapsed/Refractory Aggressive B-cell Lymphoma: A Multicenter Post-marketing Analysis

Relapsed or refractory diffuse large B-cell lymphoma poses a significant therapeutic challenge. The approval of polatuzumab, in combination with bendamustine and rituximab, represents a new treatment option. To clarify post-marketing use of polatuzumab-based therapy, we pooled data from 5 medical centers in the United States. We report that the application, toxicity, and outcomes vary from results reported in the pivotal trial. Introduction: Polatuzumab vedotin is approved therapy in the United States for relapsed/refractory diffuse large B-cell lymphoma in combination with bendamustine and rituximab (Pola+BR). However, the safety and efficacy of Pola+ BR outside of a clinical trial setting is unknown. Patients and Methods: We analyzed use of pola-based therapy at 5 centers in the United States, including dose, response rates, progression-free survival (PFS), survival, and toxicity. Results: Sixty-nine patients with aggressive B-cell lymphoma, including 66 with diffuse large B-cell lymphoma/high-grade B-cell lymphoma and 84% refractory to prior therapy, were treated. Responses occurred in of 50%, including 24% complete response. Median duration of response was 5.1 months, PFS was 2.0 months, and survival was 5.3 months, at 4 months median follow-up. Inferior PFS was associated with prior refractory disease (median, 57 days vs. not reached; P = .003) and lack of response to Pola+BR (PFS, 27 days vs. 152 days; P < .001). Discontinuation owing to planned cellular therapy was seen in 36% and owing to toxicity occurred in 12%; unplanned hospitalizations occurred in 36%. Conclusions: We conclude that commercial Pola is applied to highly refractory lymphomas at our centers, often with intent to bridge to subsequent therapy. Although some clinical benefit was observed, efficacy was inferior to clinical trial data, especially among those with refractory disease. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

Polatuzumab-based therapy is a new treatment option for relapsed or refractory diffuse large B-cell lymphoma, but there are variations in application, toxicity, and outcomes outside of clinical trials. Data from 5 medical centers in the United States showed less efficacy than in the pivotal trial, particularly in patients with prior refractory disease.