China-based Hansoh Pharmaceutical has announced that risvutatug rezetecan, a proprietary B7-H3–targeted antibody–drug conjugate (ADC), met the primary overall survival (OS) endpoint in the Phase III ARTEMIS-008 trial for small cell lung cancer (SCLC). In a prespecified interim analysis, the investigational agent demonstrated statistically significant and clinically meaningful OS improvement versus topotecan, with consistent gains in secondary endpoints such as progression-free survival (PFS) and no new safety signals.

Hansoh will now engage the National Medical Products Administration's Centre for Drug Evaluation (NMPA CDE) to advance a biologics licence application, while partner GSK progresses global Phase I and Phase III studies under its 2023 exclusive ex-China licensing agreement.

This marks the first Phase III trial to confirm an OS benefit for a B7-H3 ADC across any tumour type, addressing a substantial unmet need in SCLC where rapid relapse limits post-platinum options. The result positions Hansoh alongside peers such as MSD and Daiichi Sankyo in the competitive B7-H3 ADC landscape, following recent Phase III successes by Mabwell's candidate and a US filing by the MSD-Daiichi Sankyo partnership.