Epcoritamab Monotherapy as Outpatient Treatment for Patients With Relapsed/Refractory Diffuse Large B-Cell Lymphoma: Interim Results From EPCORE NHL-6

Background: Epcoritamab, a CD3 × CD20 bispecific antibody approved for relapsed/refractory diffuse large B-cell lymphoma (DLBCL), is administered subcutaneously with recommended 24 hours inpatient monitoring after the first full dose (FFD). EPCORE NHL-6 (NCT05451810) investigated feasibility of outpatient monitoring after FFD of epcoritamab in second-line or later (2L+) DLBCL. Methods: Patients received epcoritamab in 28-day (D) cycles (C): (0.16-mg and 0.8-mg C1 step-up doses, 48-mg full dose C1D15 onward [C1-3, QW; C4-9, Q2W; C ≥ 10, Q4W]). Primary endpoints were grade ≥ 3 cytokine release syndrome (CRS), immune effector cell–associated neurotoxicity syndrome (ICANS), and neurologic events. Patients remained ≤ 30 minutes from the hospital post-FFD and received mandatory CRS prophylaxis during C1. Results: Ninety-two patients enrolled at United States and Puerto Rico academic and community sites received ≥ 1 epcoritamab dose. With 7.6-months median follow-up, 50.0% remained on treatment. For administration and planned monitoring of FFD, 81/88 patients were outpatient and 7/88 inpatient (admitted for postdose monitoring [n = 5] and other reason [n = 2]). Twenty-four of 81 patients monitored outpatient developed CRS within 1 week post-FFD. CRS hospitalization rate was 13.6% (11/81). Overall, CRS occurred in 40.2% (grade 1-2, 38.0%; grade 3, 2.2%). ICANS occurred in 7.6% (grade 1-2, 6.5%; grade 3, 1.1%). All CRS and ICANS resolved; none led to treatment discontinuation. Overall response rate (Lugano criteria) was 62.0% (complete response rate, 42.4%). Conclusions: CRS and ICANS incidence and severity were consistent with the pivotal EPCORE NHL-1 trial findings. The results support feasibility of outpatient administration and monitoring of epcoritamab in 2L+ DLBCL without mandatory hospitalization for monitoring.