Diffuse Large B-Cell Lymphoma Patients with Bone Involvement Treated with Polatuzumab Vedotin-Based Therapy Exhibit Poorer Progression-Free Survival: A Real-World Retrospective Study in Chinese Patients
Authors: Fang Tian , Ren Kexing , Zou Liqun 
Published: December 2024

Background
Polatuzumab vedotin (pola) is a novel immunotherapy antibody-drug conjugate targeting CD79b. Recently, pola combined with rituximab, cyclophosphamide, doxorubicin, and prednisone (pola-R-CHP) in previously untreated diffuse large B-cell lymphoma (DLBCL) has been validated in clinical trials. And pola has been approved in China in 2023, but the clinical data in Chinese population is still lacking. Herein, we evaluated the efficacy and safety of pola-based regimes in lymphoma patients at West China Hospital under real-world conditions.
Methods
We conducted a single-center, retrospective chart review real-world study involving 23 patients with DLBCL at West China Hospital who received pola for the first time between 2023 and May 2024. Clinical data were extracted from medical records. Patients who discontinued treatment due to financial or other reasons were excluded. Short-term efficacy was evaluated by objective response rate (ORR), complete response (CR), partial response (PR), stable disease (SD), and disease progression (PD). Progression-free survival (PFS) and overall survival (OS) were estimated by Kaplan-Meier method. Additionally, safety profile was assessed in the study.
Results
23 patients were eligible, all patients treated with pola completed a median of 5 cycles (range: 2-6). By the end of follow-up, 12 patients completed the prescribed cycle of treatment. The most common treatment regimen was pola-R-CHP, accounting for 78.3% (18/23). Among those evaluated for efficacy, 87.0% (20/23) DLBCL patients receiving pola as first-line therapy and 13.0% (3/23) were relapsed/refractory (R/R) DLBCL patients, all of whom was POD6. The overall ORR was 86.9% (CR 56.5%, PR 30.4%). The median age of all patients was 55 years (range 21-82). After a median follow-up of 6.4 months, the median PFS for all patients was 13.1 months, with a PFS rate of 88.7% at 6 months and 88.7% at 12 months. Median OS was not achieved for all patients, with an OS rate of 95% at 6 months and 95% at 12 months. International prognostic index (IPI) scores of 22 patients were greater than or equal to 2 points, 11 patients had double hit lymphoma (DEL), and 11 patients had P53 expression levels greater than or equal to 50%. 30.4% (7/23) patients with bone involvement and the other without bone involvement, PFS were statistically significant in both groups (P=0.024). The PFS rate at 6 and 12 months was 62.5% in patients with bone involvement. There was no statistical significance in OS between the two groups (P=0.127), but there was a separation trend. Furthermore, pola-based treatment was generally well-tolerated. No grade 4 or higher adverse events were reported.
Conclusion
Pola-based regimens represent a promising treatment option for Chinese patients with previously untreated and R/R DLBCL. Our findings demonstrate significant efficacy of pola-based regimens.
Keywords: Polatuzumab Vedotin, efficacy, safety, lymphoma, real-world study.