GSK reported that its China Phase 3 study of a B7-H3 antibody-drug conjugate hit the main endpoint in advanced or relapsed small cell lung cancer. The experimental ADC, risvutatug rezetecan (ris-rez), showed statistically significant and clinically meaningful improvements in overall survival versus standard chemotherapy with topotecan, according to the company. GSK said the trial represents the first clear Phase 3 survival extension for an ADC in any tumor type, and it plans to use the China data to support a regulatory filing there. The drug is licensed from Hansoh, with Hansoh holding commercial rights in China, Hong Kong, Macau, and Taiwan. A broader global study in extensive-stage small-cell lung cancer is ongoing, with results expected next year. The outcome strengthens GSK’s oncology pipeline strategy—particularly its push into ADCs for targets including B7-H3.