A Retrospective Study of the Efficacy and Safety of Epcoritamab in Real-world Clinical Practice: An Analysis of 19 Cases from a Single Institution.

Objective This study evaluated the efficacy and safety of epcoritamab in real-world clinical practice. Methods Data of 19 patients who received epcoritamab at Saitama Cancer Center were retrospectively analyzed. Results The median follow-up duration was 5.6 months. The overall response rate (ORR) was 73.7%, with a complete response (CR) rate of 47.4%. The ORR in patients with prior exposure to bendamustine was 64.3% (CR rate, 50%), and that of bendamustine-naïve was 100% (CR rate, 40%). The ORR in patients with a bendamustine-free period of ≤6 months was 42.9% (CR rate, 28.6%), while that of patients with a bendamustine-free period of >6 months was 85.7% (CR rate, 71.4%). The median progression-free survival (PFS) and overall survival (OS) have not yet been determined, but the values prior to exposure to bendamustine were 6.6 and 7.6 months, respectively. A comparison between the prior bendamustine exposure and naïve groups showed no significant differences in the PFS and OS. In patients with lactate dehydrogenase (LDH) levels of ≤303 U/L at the start of epcoritamab, the median PFS and OS were not yet reached, while in those with LDH levels of >303 U/L, the median PFS and OS were 2.3 and 3.0 months, respectively. Treatment-emergent adverse events (TEAEs) of grade ≥3 severity occurred in 18 of the 19 patients (94.7%), and in 2 of the 19 patients (10.5%), the emergence of TEAEs necessitated treatment discontinuation. Cytomegalovirus (CMV) reactivation occurred in 11 patients (57.9%). Conclusion Careful attention should be paid to aggressive cases and those with CMV reactivation.