Subcutaneous epcoritamab monotherapy in Japanese adults with relapsed/refractory diffuse large B-cell lymphoma

Epcoritamab is a subcutaneously administered CD3xCD20 bispecific Ab that showed deep, durable responses with a manageable safety profile in patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) in the global multicenter pivotal phase II trial EPCORE NHL-1. Here, we present results from the similar EPCORE NHL-3 phase I/II trial evaluating epcoritamab monotherapy in Japanese patients with R/R CD20⁺ B-cell non-Hodgkin's lymphoma previously treated with two or more lines of therapy. Epcoritamab was dosed subcutaneously in 28-day cycles; once weekly during cycles 1–3, every 2 weeks during cycles 4–9, and every 4 weeks from cycle 10 until disease progression or unacceptable toxicity. Step-up dosing and cytokine release syndrome (CRS) prophylaxis were used during treatment cycle 1. As of January 31, 2022, 36 patients received treatment with 48 mg epcoritamab monotherapy. At a median follow-up of 8.4 months, overall response and complete response rates by independent review committee were 55.6% and 44.4%, respectively. The median duration of response, duration of complete response, and overall survival were not reached at the time of data cut-off. The most common treatment-emergent adverse events of any grade were CRS (83.3%), injection-site reactions (69.4%), infections (44.4%), neutropenia (38.9%), hypokalemia (27.8%), and decreased lymphocyte count (25.0%). Cytokine release syndrome occurrence was predictable; events were primarily low grade (grade 1–2), all resolved, and none led to treatment discontinuation. These encouraging results are consistent with previous findings and support the ongoing clinical evaluation of epcoritamab for the treatment of R/R DLBCL, including in earlier treatment lines.