Etentamig BCMA×CD3 Bispecific Hits 66% ORR with Half-the-Usual CRS in Triple-Class–Exposed Myeloma

Etentamig, a bivalent BCMA×CD3 T-cell engager engineered with low-affinity CD3 and a silenced Fc, was pooled across two Phase 1/1b studies (NCT03933735; NCT05650632) in relapsed/refractory multiple myeloma after ≥3 lines (n = 146; median 4 lines). Dosing 60 mg Q4W or 40 mg Q3W plus step-up yielded a 66% ORR and ≥VGPR in 54%, with mDOR and mPFS not reached for a median duration of follow-up of 13 months. The 12-month estimatesof mDOR was 71% and of mPFS was 55%. Grade ≥3 toxicities (79%; neutropenia 38%, anemia 23%) led to discontinuation in 9%, yet CRS (cytokine release syndrome) occurred in just 30% (no ≥G3), roughly half the 54–72% seen with the first-in-class bispecific teclistamab, whose real-world ORR sits at 63-67% and 6-month PFS at 53%.