Fixed-Duration Epcoritamab Plus R2 Drives Favorable Outcomes in Relapsed or Refractory Follicular Lymphoma

Epcoritamab is a subcutaneous CD3xCD20 bispecific antibody approved as monotherapy for relapsed/refractory (R/R) follicular lymphoma (FL). We evaluated fixed-duration epcoritamab with rituximab plus lenalidomide (R2) in R/R FL in arm 2 of EPCORE® NHL-2 (phase 1b/2; NCT04663347). Patients received epcoritamab (2 step-up doses, then 48-mg full doses) for up to 2 years and R2 for up to 12 cycles (28 days/cycle). Primary endpoint was overall response rate (ORR) per investigator assessment (Lugano criteria). As of September 21, 2024, 108 patients received ≥1 epcoritamab dose in expansion (median follow-up, 28.2 months). Median age was 65 years; 57% had 1 prior line of therapy. ORR and complete response (CR) rate were 96% and 88%; CR rates in patients with high-risk features were 90% (primary refractory), 82% (refractory to anti-CD20 and an alkylating agent), and 83% (disease progression within 24 months of first-line therapy). Two-year estimates for remaining in CR, progression-free survival, overall survival, and not starting next antilymphoma therapy were 82%, 76%, 90%, and 84%, respectively. Minimal residual disease negativity was observed in 86% of evaluable patients (clonoSEQ® assay). Common treatment-emergent adverse events (TEAEs) included neutropenia (65%), COVID-19 (59%), and cytokine release syndrome (CRS; 51%). Grade (G) ≥3 TEAEs occurred in 87% of patients; 5 had G5 TEAEs (all COVID-19). CRS events were mostly low grade (38% G1, 11% G2, 2% G3), all resolved, and none led to epcoritamab discontinuation. Fixed-duration epcoritamab plus R2 demonstrated deep, durable responses with manageable safety and favorable outcomes in R/R FL, irrespective of risk features.