Hansoh and GSK's B7-H3 ADC shows progression-free survival benefit in phase 3 osteosarcoma trial in China

Hansoh Pharmaceutical, in partnership with GSK, announced that its B7‑H3‑directed antibody‑drug conjugate (ADC) met the primary endpoint in a phase 3 study of relapsed osteosarcoma patients in China. The trial demonstrated a statistically significant extension of progression‑free survival compared with standard chemotherapy.

The study enrolled patients who had progressed after at least two prior lines of systemic therapy. Participants receiving the ADC, risvutatug rezetecan (ris‑rez), experienced longer disease control than those on chemotherapy, and secondary analyses suggested benefits in overall survival without new safety concerns.

GSK CEO Luke Miels highlighted the importance of the result for children with cancer, noting that any advancement that helps this vulnerable group is a positive step. While detailed data have not yet been released, Hansoh indicated confidence in the findings and is preparing a regulatory filing in China.

The positive outcome also supports the broader Embold Sarcoma‑202 global trial, where GSK is evaluating the same ADC in various advanced sarcoma subtypes, including osteosarcoma, potentially expanding its therapeutic reach.