China-based Hansoh Pharmaceutical Group (HKEX: 03692) announced that HS-20093 (risvutatug rezetecan; Ris-Rez), its proprietary B7-H3-directed antibody-drug conjugate licensed to GSK outside Greater China, met the primary endpoint in the pivotal ARTEMIS-011 Phase III trial. The result positions Hansoh to file a biologics license application in China and represents the first Phase III randomized evidence for an ADC in this heavily pretreated population.
ARTEMIS-011 compared HS-20093 against chemotherapy, with progression-free survival assessed by an independent review committee as the primary endpoint. The trial reported a statistically significant and clinically meaningful PFS improvement in favor of HS-20093. Consistent benefits were also observed across secondary endpoints including overall survival and investigator-assessed PFS, though no numerical data were disclosed in the announcement; detailed results are expected at an upcoming international oncology congress. The safety profile was described as consistent with prior findings, with no new safety signals identified.
HS-20093 targets B7-H3 (CD276), an immune checkpoint protein broadly overexpressed in osteosarcoma and other solid tumors, and delivers a topoisomerase I inhibitor payload following receptor-mediated internalization. Relapsed and refractory osteosarcoma has few established options beyond salvage chemotherapy. The REGOBONE Phase II randomized trial of regorafenib (Stivarga) reported a median PFS of 4.0 months versus 1.0 month for placebo in a comparable refractory population, and sorafenib (Nexavar) produced a 4-month PFS rate of 46% in a single-arm Phase II study — together representing the most cited efficacy benchmarks in the indication. Cross-trial comparisons are limited by differences in study design, duration, and patient populations.