Pola-R-CHP in previously untreated diffuse large B-cell lymphoma: Real-world data in Russia

Abstract

Abstract Introduction: Polatuzumab vedotin in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (R-CHP) was approved for previously untreated diffuse large B-cell lymphoma (DLBCL) the in Russian Federation in 2022. In 2024, Pola-R-CHP regimen was included into the national Clinical Guidelines. The aim of our study was to assess the efficacy of Pola-based treatment in first-line DLBCL using real-world data. Methods: This retrospective, observational multicenter study included 76 adult patients (pts) with DLBCL who received first-line polatuzumab vedotin–based therapy between 2022 and 2025 in 21 centers in Russia. The median age was 63 years (range: 22–80), and 47 pts (61.8%) were male. Histological subtypes included 63 pts (82%) DLBCL NOS, with non-GCB subtype in 57.8% and GCB subtype in 42.2%; newly diagnosed transformations of indolent B-cell lymphomas - 7 (9.2%); high-grade B-cell lymphoma - 3 (3.9%); other rare variants (one case each): T-cell/histiocyte-rich large B-cell lymphoma, primary mediastinal large B-cell lymphoma, and primary large B-cell lymphoma of immune-privileged sites. At diagnosis, 69 pts (90.8%) had stage III–IV disease, 38 (50%) presented with B-symptoms, 51 (61.7%) - ECOG >2, 41 (53.9%) - bulky disease (≥7.5 cm). Based on IPI, 65 pts (85.5%) were classified as intermediate-high or high risk (IPI 3–5). Treatment regimens included: Pola-R-CHP - 71 pts (93.4%), Pola-R-miniCHP - 2 (2.6%), Pola-R-EPOCH - 2 (2.6%), Pola-CHP - 1 (1.3%). The primary endpoints were, objective response rate (ORR), complete response rate (CR), and progression-free survival (PFS). Secondary endpoints were: treatment completion rate, overall survival (OS). Multivariate analysis for OS and PFS was performed using Cox proportional hazards regression. Results: As of the data cut-off (July 2025), the median number of treatment cycles was six (range: 1–6). The full course of treatment was completed in 62 pts (81.6%). Among pts who completed treatment, 90.3% (56/62) underwent end-of-treatment assessment via PET/CT. A complete metabolic response (CMR; DC1–3) was achieved in 85.7% (48/56). Interim assessment after 3 cycles was conducted in 65 pts (85.5%), with 50 evaluated by PET/CT: complete responses (CR) were 63,1% (41/65), including 37 CMR. Among 24 pts with partial response at interim, 41.7% (10/24) converted to CR before therapy completion. The hematological toxicity rates were: neutropenia 67.1%, leukopenia 42.1%, anemia 40.8%, thrombocytopenia 2.6%. Non-hematologic adverse events: nausea 25.0%, diarrhea 10.5%, infections 5.3%, peripheral neuropathy 3.9%. Grade ≥3 adverse events occurred in 38.2% (29/76), mainly due to neutropenia and febrile neutropenia (19.7%). Dose reductions due to hematologic toxicity were required in 4 patients (5.3%). At the time of analysis 71 pts (93.4%) were alive, 5 (6.6%) had died: 2 from disease progression and 3 from unrelated causes. Disease progression occurred in 3 pts (3.9%). Median follow-up 16.8 months, median PFS and OS were not reached, 1-year PFS – 89,9%, 1-y OS – 91.2%. Only lung involvement was independently associated with both PFS (HR 7.456; 95% CI: 1.237–44.920; p = 0.028) and OS (HR 7.133; 95% CI: 1.186–42.893; p = 0.032). Conclusions: This first multicenter real-world study of polatuzumab vedotin–based treatment in Russia demonstrates high efficacy and an acceptable safety profile in a predominantly high-risk (IPI 3–5) previously untreated DLBCL population. The clinical outcomes are consistent with global trial data, supporting the regimen's reproducibility and effectiveness in routine practice.