Hansoh’s B7-H3-directed antibody-drug conjugate risvutatug rezetecan (ris-rez), partnered with GSK, logged another phase 3 progression-free survival win in China for relapsed osteosarcoma. The study compared the ADC to chemotherapy in patients who progressed or relapsed after at least two prior systemic lines, with Hansoh and GSK stating the trial hit its primary PFS endpoint. GSK said secondary endpoints reflected consistent benefit and reported no new safety signals, framing the result as part of broader efforts to extend the ADC’s use beyond second-line small cell lung cancer. A global phase 1b/2 trial is also referenced as preparing to evaluate the asset across sarcoma indications. The update reinforces momentum in the B7-H3 ADC class, where multiple programs are converging on pediatric- and adolescent-facing oncology needs and underserved indications.