Phase 1b study: JNJ-78278343 KLK2/CD3 bispecific and JNJ-95298177 PSMA ADC for prostate cancer.

This study by Janssen Research & Development evaluates combined dose finding and expansion using a Bayesian Optimal Interval design. It investigates JNJ-78278343, a T-cell redirecting KLK2/CD3 bispecific antibody, with JNJ-95298177, a PSMA-targeted tubulin inhibitor ADC, in patients with metastatic castration-resistant prostate cancer to determine the recommended phase 2 dose and assess safety and anti-tumor activity. In post-ARPI mCRPC, SoC options include taxanes, ^177Lu-PSMA-617, and cabazitaxel (± PARP inhibitors for HRR-mutated disease); this dual-antigen strategy explores deeper cytoreduction than single-modality approaches.