Subgroup analysis of elderly patients (≥60 years) with diffuse large B-cell lymphoma in the phase 3 POLARIX study

In the phase 3 POLARIX study, polatuzumab vedotin plus rituximab, cyclophosphamide, doxorubicin, and prednisone (Pola-R-CHP) improved progression-free survival (PFS) versus rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in patients with previously untreated diffuse large B-cell lymphoma (DLBCL). This post hoc subgroup analysis of POLARIX evaluated the efficacy and safety of Pola-R-CHP versus R-CHOP in elderly patients ≥60, ≥65, ≥70, and ≥75 years. As of June 15, 2022 (median follow-up 40 months), 629 patients ≥60 years were included (Pola-R-CHP, n = 311; R-CHOP, n = 318). Clinically meaningful improvements in PFS with Pola-R-CHP versus R-CHOP were observed across all age groups, particularly in patients ≥70 years whereby the risk of disease progression, relapse or death was reduced by 37% (unstratified hazard ratio [HR] 0.63; 95% confidence interval [CI]: 0.41-0.96). In patients ≥ 60 years, overall survival was similar with Pola-R-CHP versus R-CHOP (unstratified HR 0. 99; 95% CI: 0.67 -1.47 ). Safety profiles were similar for Pola-R-CHP versus R-CHOP among patients ≥60 years, including rates of grade 3-4 adverse events (AEs; 62.7% vs 61.5%), grade 3-5 infections (15.0% vs 12.9%), and grade 5 AEs (3.6% vs 3.2%); no novel toxicities were reported. Incidence of grade 3-4 febrile neutropenia was higher with Pola-R-CHP than R-CHOP (16.3% vs 7.6%), highlighting the importance of G-CSF prophylaxis in elderly patients receiving Pola-R-CHP. The benefit-risk profile favored Pola-R-CHP versus R-CHOP in elderly patients with previously untreated DLBCL. This trial was registered at ClinicalTrials.gov as #NCT03274492.