GSK reported that its Hansoh-partnered antibody-drug conjugate risvutatug rezetecan (ris-rez) met the primary endpoint in a Phase 3 study in China in advanced or relapsed small-cell lung cancer. The ADC, targeting B7-H3, improved overall survival versus standard-of-care topotecan, which positions the therapy as a key part of both companies’ B7-H3 oncology strategy. GSK said the study also showed statistically significant and clinically meaningful improvements across secondary measures such as delaying tumor progression, while describing the safety profile as manageable. Company disclosure also highlighted that it is the first time a B7-H3-targeted ADC has clearly lengthened survival in a Phase 3 trial in any tumor type. The results are expected to support a China regulatory filing, with Hansoh holding commercial rights in China, Hong Kong, Macau and Taiwan. GSK retains ownership elsewhere and said a global Phase 3 program in extensive-stage SCLC is underway, with readouts planned next year. The Phase 3 milestone also reinforces GSK’s recent push into oncology via China-linked deals, including an earlier $185 million upfront payment for majority rights to ris-rez and a separate B7-H3 program mo-rez that is also in late-stage development.