Hansoh/GSK: Ris‑Rez cuts progression or death risk by 67% vs chemotherapy in relapsed osteosarcoma (China phase III)

Trial results

Hansoh’s pivotal phase III ARTEMIS‑011 in China met its primary endpoint, demonstrating a statistically significant and clinically meaningful improvement in Independent Review Committee‑assessed progression‑free survival (PFS) for risvutatug rezetecan (Ris‑Rez) versus chemotherapy in patients with osteosarcoma that progressed or relapsed after at least two prior systemic therapies. After a median follow‑up of 7.1 months, Ris‑Rez reduced the risk of disease progression or death by 67% (HR 0.33; 95% CI 0.20–0.55; p<0.0001). Median PFS was 5.5 months with Ris‑Rez versus 1.4 months with chemotherapy. The late‑breaking results were presented at the ESMO Congress 2026 and will support a regulatory submission by Hansoh in China.

Safety

Safety findings were reported as consistent with prior data in this tumour type. Grade 3 or higher treatment‑related adverse events (TRAEs) occurred in 93% of patients receiving Ris‑Rez and 83% of patients receiving chemotherapy, with haematologic events the most common severe TRAEs. TRAEs led to treatment discontinuation in 4% of Ris‑Rez patients versus 2% with chemotherapy.

Context and next steps

ARTEMIS‑011 was conducted by Hansoh Pharma. GSK holds exclusive rights to develop and commercialise Ris‑Rez outside mainland China, Hong Kong, Macau and Taiwan and is advancing a global development programme across multiple solid tumours. Data from ARTEMIS‑011 will inform dose selection and GSK’s ongoing global studies, including a phase II trial in advanced osteosarcoma and soft tissue sarcoma (EMBOLD Sarcoma‑202).