Risvutatug rezetecan (Ris-Rez) versus gemcitabine and docetaxel (GD) in heavily pretreated patients (pts) with relapsed or refractory (R/R) osteosarcoma: Primary results from the phase 3 ARTEMIS-011 study

doi:10.1016/j.annonc.2026.10.1284

ARTEMIS-011

Patient / Population Intervention / Exposure Comparison Outcome

In Chinese patients with heavily pretreated relapsed or refractory osteosarcoma, risvutatug rezetecan improved progression-free survival assessed by blinded independent central review compared with gemcitabine and docetaxel.

N

122patients

Design

Multicentre, open-label, randomised (2:1) phase 3 trial in Chinese patients aged 12 years or older with relapsed or refractory osteosarcoma who had progressed or relapsed after at least 2 prior lines of systemic therapy, comparing risvutatug rezetecan with gemcitabine and docetaxel (NCT06935409).

Endpoint

Progression-free survival assessed by blinded independent central review (BICR).

ResultBICR-assessed median PFS 5.5 vs 1.4 months with gemcitabine and docetaxel (HR 0.33; P < 0.0001). Investigator-assessed median PFS 5.6 vs 1.0 months. Overall survival was immature (HR 0.51). Grade ≥3 TEAEs 92.5% vs 83.3%. Treatment-related serious adverse events 63.8% vs 28.6%, mainly driven by haematological toxicities. Discontinuation due to treatment-related adverse events 3.8% vs 2.4%. One treatment-related interstitial lung disease (grade 2, resolved) with risvutatug rezetecan and no treatment-related deaths. Median follow-up 7.1 months.

Xie L, Yao W, Hua Y, et al. Annals of Oncology. 2026. 10.1016/j.annonc.2026.10.1284

Discussion & critique

The trial shows a large improvement in BICR-assessed progression-free survival over gemcitabine and docetaxel in a heavily pretreated population that included adolescents, and the investigator-assessed PFS agrees with it. Median follow-up was only 7.1 months and overall survival is immature, so the HR of 0.51 is a trend and not proof of a survival benefit. The design was open label, which central review only partly offsets, and all patients were Chinese, which may limit how far the results generalise. The abstract gives no confidence intervals, response rates or quality-of-life data, and treatment-related serious adverse events were more than twice as common with the drug, mainly haematological.