SHANGHAI, July 28, 2026
Hansoh Pharmaceutical Group Co., Ltd. announced that risvutatug rezetecan (Ris-Rez/HS-20093), its proprietary B7-H3-directed antibody-drug conjugate (ADC), met the primary endpoint in the pivotal Phase 3 ARTEMIS-011 trial in advanced osteosarcoma. The registrational study evaluated patients whose osteosarcoma had progressed or relapsed after at least two prior lines of systemic therapy. According to Hansoh Pharma, Ris-Rez produced a statistically significant and clinically meaningful improvement in progression-free survival (PFS), as assessed by an Independent Review Committee (IRC), compared with chemotherapy. Secondary endpoints, including overall survival (OS) and investigator-assessed PFS, showed consistent benefit, while the safety profile remained consistent with previously reported findings and no new safety signals were identified. Hansoh plans to engage with the Center for Drug Evaluation (CDE) of China’s National Medical Products Administration (NMPA) to advance preparations for a Biologics License Application (BLA).
ARTEMIS-011 Delivers Positive Phase 3 Osteosarcoma Results
The positive ARTEMIS-011 Phase 3 results represent an important clinical milestone for Hansoh Pharma’s B7-H3 ADC program and could support a potential new therapeutic approach for patients with heavily pretreated osteosarcoma. The company has not yet disclosed detailed numerical efficacy results, with complete findings expected to be presented at an upcoming international oncology congress. However, Hansoh reported that the study achieved its primary endpoint of IRC-assessed progression-free survival, demonstrating superiority over chemotherapy that was both statistically significant and clinically meaningful. The company also reported consistent benefit across key secondary measures, including overall survival and investigator-assessed PFS. Importantly, the trial did not identify new safety signals, with the safety profile remaining consistent with previous clinical experience involving Ris-Rez. These findings follow previously announced positive pivotal data for Ris-Rez in advanced or relapsed small-cell lung cancer, giving the investigational ADC positive Phase 3 outcomes across two distinct tumor types.
B7-H3 ADC Targets Major Unmet Need in Osteosarcoma
Osteosarcoma is the most common malignant bone tumor and frequently affects children, adolescents and young adults, with a median age at onset of approximately 20 years. According to Hansoh Pharma, around 20% to 30% of patients with localized osteosarcoma and approximately 80% of patients with metastatic disease eventually progress to advanced recurrent or metastatic disease. The five-year survival rate for advanced osteosarcoma remains approximately 20%, highlighting the substantial need for new treatment strategies. Options are particularly limited after failure of first- and second-line systemic therapies, with no clearly defined global standard of care for recurrent or refractory disease. Ris-Rez is designed to selectively target the B7-H3 antigen expressed on tumor cells and deliver a topoisomerase inhibitor payload directly into those cells. This targeted ADC strategy is intended to generate potent antitumor activity while limiting systemic exposure to its cytotoxic payload.
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Hansoh Pharma Prepares Regulatory Path for Ris-Rez
Following the positive ARTEMIS-011 results, Hansoh Pharma plans near-term discussions with China’s CDE to prepare for a potential BLA submission for Ris-Rez in osteosarcoma. Risvutatug rezetecan consists of a fully human B7-H3 monoclonal antibody covalently linked to a topoisomerase inhibitor payload and represents the core asset within Hansoh’s B7-H3-directed ADC portfolio. The candidate has reached Phase 3 development in China across osteosarcoma, small-cell lung cancer, non-small cell lung cancer and esophageal squamous cell carcinoma, while additional proof-of-concept studies are evaluating its potential in head and neck, prostate and colorectal cancers and other solid tumors. Hansoh Pharma granted GSK an exclusive worldwide license outside mainland China, Hong Kong, Macau and Taiwan in December 2023 to develop, manufacture and commercialize Ris-Rez, with GSK advancing clinical development internationally. The positive ARTEMIS-011 outcome strengthens the clinical evidence supporting B7-H3-directed ADC therapy and positions Ris-Rez for a potential regulatory submission in a difficult-to-treat osteosarcoma population. Detailed data from the Phase 3 study will be important for assessing the magnitude and durability of the reported clinical benefit.
Source: Hansoh Pharma press release
