CS1-BCMA bispecific CAR T cells

**CS1-BCMA bispecific CAR T cells** are an autologous T cell therapy engineered with a tandem bispecific chimeric antigen receptor (CAR) incorporating novel anti-CS1 scFv (clone 7A8D5) and anti-BCMA scFv (clone 4C8A) linked to 4-1BB and CD3ζ signaling domains. This design enables T cell activation upon binding either **CS1 (SLAMF7)** or **BCMA (B-cell maturation antigen)** on target cells, addressing antigen escape in multiple myeloma (MM) where single-target therapies like BCMA CAR-T fail due to BCMA loss while CS1 expression persists. Developed for relapsed/refractory MM (RRMM), it showed an 81% overall response rate (ORR), 38% stringent complete response (sCR), and 100% minimal residual disease (MRD) negativity in bone marrow-involved patients in a phase 1/2a trial (NCT04662099), with median CAR-T persistence of 406 days and soluble BCMA as a biomarker for response monitoring. Safety profile includes 38% cytokine release syndrome (mostly grade 1-2), no immune effector cell-associated neurotoxicity syndrome (ICANS), and manageable hematologic toxicities; it demonstrated efficacy post-prior BCMA CAR-T failure and in patients with high CS1/BCMA expression on MM cells.[1][4]

Other names

BCMA/CS1 bispecific CAR-T cellsbispecific CS1-BCMA CAR-T cells