GSK and Hansoh Pharmaceutical reported that risvutatug rezetecan (ris-rez), a B7-H3 targeted antibody-drug conjugate, met its primary endpoint of overall survival in a Phase 3 small cell lung cancer study in China. The trial outcome positions the program as a potential approval catalyst in a market where GSK’s ADC franchise has been expanding. GSK said the results showed statistically significant and clinically meaningful survival improvements versus standard-of-care chemotherapy (topotecan), and it described consistent benefits across secondary measures including delaying tumor progression. The companies did not provide numerical specifics in the release. GSK is also advancing another Hansoh-linked ADC in later-stage development and has additional ris-rez readouts planned globally, including an extensive-stage SCLC Phase 3 expected to report in 2027. The China Phase 3 win increases the likelihood of regulatory momentum for a B7-H3 platform with broad solid-tumor ambitions.