Efficacy and safety of brentuximab vedotin in relapsed or refractory diffuse large B-cell lymphoma: A systematic review and meta-analysis.

e19065 Background: Relapsed or refractory (r/r) diffuse large B-cell lymphoma (DLBCL) remains a major clinical challenge, with a significant proportion of patients failing standard R-CHOP therapy. While CAR T-cell therapy has transformed outcomes for eligible patients, its use is limited by cost, logistics, and toxicity. Brentuximab vedotin (BV), an anti-CD30 antibody-drug conjugate, has shown activity in CD30-positive lymphomas. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of BV in r/r DLBCL. Methods: Embase, PubMed, Cochrane, and ClinicalTrials.gov were searched through December 2025. Five studies comprising 260 patients were included. Pooled analyses of complete response rate (CRR), overall response rate (ORR), hematologic toxicity, peripheral neuropathy, treatment discontinuation, and mortality were performed using random-effects models in R 4.5.2 using the “metafor” package. Heterogeneity was quantified using I² statistics, and leave-one-out sensitivity analyses were conducted to explore variability. Results: The pooled CRR was 0.42 (95% CI: 0.17–0.72; I² = 84.8%), and ORR was 0.72 (95% CI: 0.40–0.91; I² = 54.1%), indicating meaningful clinical activity. Grade 3/4 hematologic toxicities included neutropenia (0.40; 95% CI: 0.32–0.48), thrombocytopenia (0.12; 95% CI: 0.01–0.61), and anemia (0.13; 95% CI: 0.02–0.57). Severe adverse events occurred in 76% of patients (95% CI: 0.54–0.90; I² = 84.3%). Grade 3/4 peripheral neuropathy was low (0.06; 95% CI: 0.03–0.12), and treatment discontinuation due to toxicity occurred in 17% (95% CI: 0.08–0.34). All-cause mortality was 6% (95% CI: 0.01–0.24). Conclusions: BV shows meaningful clinical activity in r/r DLBCL, with nearly three-quarters of patients achieving an objective response and a substantial proportion achieving complete remission. Hematologic toxicity and treatment discontinuation are notable, but severe neurotoxicity is rare. These findings support BV as a therapeutic option in r/r DLBCL.