Polatuzumab vedotin in relapsed or refractory diffuse large b‐cell lymphoma patients: a matched‐control analysis from the thai lymphoma study group (tlsg)

Treatments of patients with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) represent an unmet clinical need. Polatuzumab vedotin (Pola), an anti-CD79b antibody-drug-conjugate (ADC), combined with bendamustine-rituximab (BR), has recently been approved for these patients. However, there were limited data on real-life studies in R/R DLBCL, especially in Thailand. R/R DLBCL patients who received Pola-based regimens as a salvage treatment between 1 April 2021 and 30 March 2022 from the nationwide multi-center in Thailand were included in determining efficacy and safety in the real-world setting. Age, sex, and prior treatments-matched controls were selected from the database of the Thai lymphoma registry. The Pola group and historical control R/R DLBCL patients were compared. Thirty-five patients who received Pola-based treatment (Pola-BR 54.3% and Pola-R 45.7%) were included. The median age was 66 years (IQR 58–79), and the median number of prior treatments was 2 (range 1–4). The overall response rate (ORR) was 62.8%, with complete remission and partial remission of 17.1% and 45.7%. With a median follow-up of 11.8 months, the median progression-free survival (PFS) and overall survival (OS) were 10.6 months and 12.8 months, respectively. Grade 3–4 adverse events (AEs) were mainly hematological: anemia (8.6%), thrombocytopenia (5.7%), neutropenia (22.5%), and febrile neutropenia (8.6%). Compared with 180 matched patients who received non-pola-based therapy, there was a significantly higher ORR in Pola-based salvage treatments (62.8% vs. 33.3%, hazard ratio [HR] 3.52, 95% confidence interval [CI] 1.39-8.95, p < 0.01). The survival outcomes were also significantly superior in the Pola group: the median PFS 10.6 versus 4.2 months (HR 0.49; 95% CI, 0.29-0.85; p = 0.015), median OS 12.8 versus 7.5 months (HR 0.53; 95% CI, 0.34-0.84; p = 0.017). The use of Polatuzumab vedotin combination as a salvage treatment in R/R DLBCL demonstrated promising results with tolerable toxicities in the real-world setting. Keywords: aggressive B-cell non-Hodgkin lymphoma, chemotherapy, immunotherapy No conflicts of interests pertinent to the abstract.