First Clinical Study Of The B-Cell Maturation Antigen (Bcma) 2+1 T Cell Engager (Tce) Cc-93269 In Patients (Pts) With Relapsed/Refractory Multiple Myeloma (Rrmm): Interim Results Of A Phase 1 Multicenter Trial

Introduction: BCMA is a tumor necrosis factor (TNF) receptor superfamily transmembrane glycoprotein essential for the maturation and survival of plasma cells. CC-93269 is an asymmetric 2-arm humanized IgG TCE that binds bivalently to BCMA and monovalently to CD3ε in a 2+1 format (Seckinger A, et al. Cancer Cell. 2017;31:396-410). The CC-93269-mediated interaction between T cells and BCMA-expressing myeloma cells induces T cell receptor/CD3 crosslinking leading to T cell activation, and release of proinflammatory cytokines and cytolytic enzymes, resulting in myeloma cell death. In preclinical studies with CC-93269 and related molecules, 2+1 BCMA TCEs induced tumor regression in animal models and promoted myeloma cell death in primary pt myeloma cells. Here we report interim results from a phase 1 dose-finding study (CC-93269-MM-001; NCT03486067) evaluating CC-93269 in pts with RRMM.