Pola-Based Framework Regimen Treating DLBCL in Real World at Renji Hospital of China

Purpose: Optimizing treatment outcomes for diffuse large B-cell lymphoma (DLBCL) remains our pursuit. Polatuzumab vedotin (Pola), an antibody-drug conjugate targeting CD79b, is a newly-developed drug that authentically improve the therapeutic effect of DLBCL. This study explores the efficacy of a Pola-based regimen in treating DLBCL at RenJi Hospital, China, and examines the impact of various patient characteristics on treatment outcomes.

Methods: The safety and efficacy of Pola, in combination with given treatments, were evaluated in a real-world cohort of DLBCL patients. Between March 25, 2023, and June 15, 2024, a total of 62 patients with diffuse large B-cell lymphoma (DLBCL) were enrolled in the study, including 43 newly diagnosed and 19 previously treated patients. As of July 1, 2024, a total of 54 patients had been evaluated. The primary endpoint was independent review committee [IRC] assessed complete response (CR) rate. The secondary endpoints were duration of response (DoR), progression-free survival (PFS), and overall survival (OS).

Results: Pola demonstrated remarkable efficacy and a tolerable safety profile. The CR rates in first-line (n=38, 18 with the germinal center B-cell (GCB) subtype), second-line (n=11, 3 with GCB), and third-line or later treatment (n=5, 3 with GCB) were 81.58%, 54.55%, and 20%, respectively. Low-risk International Prognostic Index (IPI) patients (IPI 0-2) achieved a higher CR rate (88.24%) compared to high-risk patients (IPI 3-5) with a CR rate of 62.16%. High P53 expression and CD5 positivity were associated with lower CR rates (61.11% vs. 75% and 66.67% vs. 70.97%, respectively). Patients without bulky disease had a significantly higher CR rate (81.08%) compared to those with bulky disease (47.06%). At a median follow-up of 5.5 months (IQR 3.1-9.9), PFS and OS data were not yet reached. Adverse effects primarily included pulmonary infections and agranulocytosis. Though incidence of radiographic abnormalities in the lungs was high, observed in 52.63%, 45.45%, and 40% of patients in the first-line, second-line, and third-line or later treatment groups, respectively, the incidence of severe pneumonia was relatively low, occurring in only 6 out of 54 patients (11.11%). Agranulocytosis was reported in 18.42%, 27.27%, and 20% of patients in the respective groups. Peripheral neuropathy was not observed, and 8 deaths were reported.

Conclusions: A Pola-based immunochemotherapy regimen resulted in significant CR rates in both newly diagnosed and previously treated DLBCL patients. However, high-risk IPI scores, high P53 expression, CD5 positivity, and the presence of bulky disease were associated with lower CR rates. The adverse effects, particularly immune-compromised pneumonia and agranulocytosis, necessitate meticulous monitoring and management. These findings highlight the importance of tailored therapeutic approaches to improve patient outcomes.

No relevant conflicts of interest to declare.