Introduction:Despite advances in the treatment of B-cell non-Hodgkin lymphoma (B-NHL), more efficacious, less toxic, off-the-shelf therapies are needed for patients (pts) with relapsed or refractory (R/R) disease. Epcoritamab is a novel, subcutaneously (SC) administered bispecific antibody (bsAb) that simultaneously binds to CD3 on T cells and CD20 on B cells, inducing activation and cytotoxic activity of T cells for killing of target lymphoma cells. In an open-label, phase 1/2 trial (NCT03625037), initial data demonstrated an encouraging safety profile and potent single-agent clinical activity, even at low doses, in heavily pretreated pts with R/R B-NHL (Hutchings M. EHA 2020, Poster EP1218). Herein, we present updated dose-escalation data, including initial results for the 48-mg recommended phase 2 dose (RP2D) and for pts with mantle cell lymphoma (MCL).