Three-year follow-up of epcoritamab therapy in Japanese patients with relapsed/refractory follicular lymphoma in EPCORE NHL-3

BACKGROUND: The CD3xCD20 bispecific antibody epcoritamab demonstrated deep, durable responses with manageable safety in relapsed/refractory (R/R) follicular lymphoma (FL) in EPCORE NHL-3 (phase 1/2; NCT04542824). This analysis evaluated 3-year follow-up outcomes in Japanese patients. METHODS: Adults with CD20 + FL and ≥ 2 prior lines of therapy (LOTs) received subcutaneous epcoritamab (0.16/0.8-mg step-up doses; 48-mg full doses) until disease progression or death. The primary endpoint was overall response rate (ORR). RESULTS: Twenty-one patients received epcoritamab (median age: 65 years; median prior LOTs: 4; 57.1% double refractory; 57.1% progressed within 24 months of any first-line treatment). At a median follow-up of 35 months, the ORR was 95.2% and the complete response (CR) rate was 76.2%. Median duration of response, duration of CR, progression-free survival, and overall survival were not reached. At 3 years, 66.7% and 93.3% of complete responders remained progression-free and alive, respectively. Minimal residual disease negativity was achieved in 88.9% (16/18) of evaluable patients. Common treatment-emergent adverse events included cytokine release syndrome (90.5%) and injection-site reaction (71.4%), all predominantly grade 1-2 and occurring in early treatment cycles, and none fatal. CONCLUSIONS: Epcoritamab monotherapy provided durable long-term remission with favorable safety in Japanese patients with R/R FL over 3 years of follow-up.