GSK reported that its B7-H3-targeted antibody-drug conjugate risvutatug rezetecan (risvutatug rezetecan; ris-rez) met the primary endpoint in a Phase 3 study in China for advanced or relapsed small cell lung cancer. The trial compared overall survival against standard-of-care chemotherapy topotecan and reportedly delivered “statistically significant and clinically meaningful” improvements. GSK and Hansoh positioned the result as the first positive Phase 3 overall survival readout for a B7-H3-directed ADC in any tumor type, and said the data will support a China regulatory filing. A global Phase 3 program in extensive-stage SCLC is described as ongoing, with results expected in 2027. The update strengthens GSK’s push to expand beyond its core franchises through ADC partnerships tied to solid tumor targets with high expression profiles.