Efficacy of Polatuzumab Vedotin in Chinese Patients with Diffuse Large B-Cell Lymphoma (DLBCL): A Single-Center Real-World Analysis
Authors: Yang Chunmei , Mao Liping , Wei Juying , Xie Wanzhuo , Ye Xingnong , Yang Min , Huang Jian , Zhou De , Ma Liya , Lou Yinjun , Wang Huafeng , Jin Jie , Tong Hongyan , Yu Wenjuan 
Published: December 2024

Background:

Polatuzumab vedotin (POLA) is a innovative antibody-drug conjugate (ADC) targeting CD79b, received FDA approval in 2019 for treating both newly diagnosed and relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). Clinical trials have consistently shown that POLA-based chemotherapy regimens significantly improve complete remission (CR) and progression-free survival (PFS) in high-risk newly diagnosed DLBCL and relapsed/refractory DLBCL. Preliminary real-world evidence indicates that POLA-based combination can significantly improve disease remission rates and augment the success of autologous stem cell transplantation (ASCT). However, POLA was launched in China relatively late, and the scarcity of real-world data necessitates further investigation.

Objective:

This single-center retrospective study was initiated to address the paucity of real-world data on the efficacy of POLA-based regimens among the Chinese population, aiming to contribute valuable treatment insights for clinical practice.

Methods:

We conducted a retrospective analysis of data from 21 newly diagnosed DLBCL patients who received POLA in combination with R-CHP, R-CHP+X, and other chemotherapy protocols, as well as 74 R/R DLBCL patients treated with POLA-based regimens from April 2023 to June 2024 at our institution. Inclusion criteria: (1) Pathologically confirmed diagnosis of DLBCL with measurable lesions；(2) Patients with previously untreated or relapsed/refractory (R/R) DLBCL；(3) Completion of at least one cycle of POLA-based regimen with evaluable efficacy. The primary efficacy endpoints were complete remission rate (CRR) and objective remission rate (ORR).

Results:

A total of 95 DLBCL patients were included in this study: 22% (21) newly diagnosed DLBCL patients, 54% (51) R/R DLBCL patients received second-third line regimens, and 24% (23) R/R DLBCL patients received fourth line and above regimens, also including 3 cases of transformed follicular lymphoma. The median age was 60 years (18-89), with 54% (51) males and 46% (44) females. GCB type accounted for 27% (26) and non-GCB type for 69% (66), with 27% (26) double-expressers. IPI score &lt;3 accounted for 29% (28) and IPI score ≥3 for 71% (67). Lugano stage I-II accounted for 20% (19) and stage III-IV for 80% (76). Large masses were observed in 22% (21) of patients.

The median follow-up was 5 months. Among the 21 newly diagnosed DLBCL patients, 19 were eligible for assessment. The ORR was 89.5%, with 9 patients (47.4%) achieving CR and the median PFS has not been reached. Among the 51 R/R DLBCL patients received second-third line regimens, 48 were evaluable, ORR was 58.3%, with 11 patients (22.9%) achieving CR, and median PFS was 5 months. Among the 23 R/R DLBCL patients received fourth line and above regimens, ORR was 26.1%, only 1 patient (4.3%) achieving CR. The median DOR was 7.3 months and median DOCR was 8.9 months in the overall patients. Interestingly, among the 21 patients who achieved CR, only one patient experienced subsequent disease progression, suggesting that regardless of the line of treatment, once CR is achieved based on regimes including POLA, patients may experience durable disease remission.

Conclusion:

POLA-based regimens are associated with durable disease remissions and prolonged disease-free survival after achieving CR, underscoring the imperative for the prompt identification of high-risk patients and the initiation of POLA-based regimens at an early stage.