Updated Results from MajesTEC-1: Phase 1/2 Study of Teclistamab, a B-Cell Maturation Antigen x CD3 Bispecific Antibody, in Relapsed/Refractory Multiple Myeloma

Introduction: Teclistamab (JNJ-64007957) is a T-cell redirecting, bispecific IgG4 antibody that targets both B-cell maturation antigen (BCMA) and CD3 receptors to induce T-cell mediated cytotoxicity of BCMA-expressing myeloma cells. Teclistamab is under investigation in MajesTEC-1, an ongoing phase 1/2 study in patients (pts) with heavily pretreated relapsed/refractory multiple myeloma (RRMM). Results from the phase 1 study (parts 1 and 2; NCT03145181) indicated that teclistamab is well tolerated at the recommended phase 2 dose (RP2D) and has encouraging efficacy, with an overall response rate (ORR) of 65% and very good partial response or better (≥VGPR) rate of 58% in 40 pts after a median of 6.1 mo of follow-up. Here we report for the first time initial data from the phase 2 portion of MajesTEC-1 (part 3; NCT04557098) and updated results for phase 1 pts treated at the RP2D.