Obrixtamig DLL3×CD3 Adds 73% ORR to 1L ES-SCLC Chemo-IO

Obrixtamig (BI 764532) is an IV DLL3/CD3 IgG-like T-cell engager combined with carboplatin/etoposide/atezolizumab induction followed by obrixtamig plus atezolizumab maintenance in the Phase 1 DAREON-8 trial (NCT06077500). In efficacy-evaluable ES-SCLC patients (n=44), confirmed ORR was 73% (CR 9%, PR 64%) and DCR was 91%; median PFS and DOR were not reached, with 6- and 9-month PFS rates of 76% and 61%. Obrixtamig-related CRS occurred in 52%, discontinuations due to TRAEs were uncommon, and the ORR compares favorably with IMpower133 chemo-atezolizumab benchmarks of ~60% ORR and 5.2-month median PFS.