Preliminary analysis of a multicenter study of Pola-R-CHP in untreated Japanese patients with DLBCL (POLASTAR)

Polatuzumab vedotin plus rituximab, cyclophosphamide, doxorubicin, and prednisone (Pola-R-CHP) was approved in Japan for the treatment of previously untreated diffuse large B-cell lymphoma (DLBCL) in 2022, based on findings of the POLARIX study (NCT03274492). Reports on real-world usage of Pola-R-CHP are lacking. Here we report safety and response rates at end of treatment (EOT) for Pola-R-CHP in Japan from the real-world observational POLASTAR study (jRCT1071220082). Patients (≥ 18 years) with previously untreated DLBCL who were scheduled to receive Pola-R-CHP were enrolled. The primary endpoint was overall survival. As of December 20, 2023, the full analysis set (FAS) included 192 of the initial 199 patients enrolled. Median age was 71.0 years (range 30-91). In the FAS, 99 (51.6%) patients had Grade ≥ 3 adverse events (AEs), 29 (15.1%) had serious AEs, and 15 (7.8%) discontinued polatuzumab vedotin due to AEs. In the efficacy-evaluable population at EOT (n = 141), the overall response rate was 95.0% [95% confidence interval (CI), 90.1-97.6], and the complete response rate was 87.9% (95% CI, 81.5-92.3). These results are consistent with published data from POLARIX. The POLASTAR study is ongoing; the recruitment target of 500 patients has been reached.Clinical trial registration: Japan Registry of Clinical Trials (jRCT1071220082).