DB-1311/BNT324 (B7-H3 ADC) logs 28% responses and 8-mo rPFS in late-line CRPC

In the Phase 1/2 dose-optimization study NCT05914116, 65 heavily pre-treated metastatic CRPC patients (median 3 prior lines; 94% docetaxel, 15% Lu-177) received 6 mg/kg or 9 mg/kg Q3W DB-1311/BNT324; among 43 RECIST-measurable pts, unconfirmed ORR was 27.9% (12 PR; 8 confirmed) with 95% disease control, median rPFS 8.3 mo (6-mo rate 87%), and DOR not yet reached. Grade ≥3 treatment-related AEs hit 40%—mainly hematologic—with 6% discontinuations and slightly higher cytopenias at 9 mg/kg, while nausea predominated at lower grades; no treatment-related deaths were seen.