BioNTech and partner DualityBio announced plans to move their B7‑H3–targeting antibody‑drug conjugate into a phase‑3 study for metastatic castration‑resistant prostate cancer after encouraging phase‑1/2 results. The partners aim to run a substantially smaller trial than a Merck‑Daiichi rival, leveraging the earlier efficacy signal to design a more efficient pivotal program. BioNTech and Duality cited tolerability and tumor responses from the dose‑escalation cohorts as the basis for the accelerated development plan. The companies said the phase‑3 will target a specific mCRPC population and will be sized to achieve regulatory endpoints while reducing patient numbers compared with competing programs. If successful, the ADC could position BioNTech beyond its vaccine franchise and intensify competition in the mCRPC immuno‑oncology landscape.