Risvutatug Rezetecan Shows 54% OS Improvement in Relapsed SCLC

Risvutatug rezetecan (Ris-Rez), a B7-H3–directed antibody-drug conjugate, significantly improved overall survival (OS) compared with topotecan in patients with relapsed small cell lung cancer (SCLC) whose disease had progressed on or after platinum-based chemotherapy, according to results from the phase 3 ARTEMIS-008 trial (NCT06498479) presented at the International Association for the Study of Lung Cancer (IASLC) 2026 World Conference on Lung Cancer (WCLC).¹

At a data cutoff of June 6, 2026 and a median follow-up of 12.2 months, median OS was 18.5 months with Ris-Rez compared with 10.3 months with topotecan, corresponding to a 54% reduction in the risk of death (HR, 0.46; 95% CI, 0.35-0.62; P < .0001), with consistent OS benefit across relevant subgroups.

“Ris-Rez demonstrated a statistically significant and clinically meaningful overall survival benefit over topotecan in patients with SCLC that progressed after platinum-based therapy, with a favorable safety profile,” said Jie Wang, MD, PhD, professor at the National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences Peking Union Medical College, in Beijing, China, according to a news release from the IASLC. “These results suggest the potential of Ris-Rez to define a new standard of care in relapsed SCLC.”²

Trial Design

ARTEMIS-008 is a multicenter, open-label, randomized phase 3 trial conducted in China that randomly assigned 461 patients 1:1 to Ris-Rez at 8.0 mg/kg every 3 weeks or topotecan at 1.2 mg/m² on days 1 through 5 every 3 weeks. More than 80% of patients had previously received a PD-(L)1 inhibitor. The primary end point was OS; key secondary end points included progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and safety.¹

Additional Efficacy Findings

By blinded independent central review, median PFS was 7.2 months with Ris-Rez vs 3.0 months with topotecan (HR, 0.33; 95% CI, 0.25-0.42). ORR was 58.3% with Ris-Rez vs 12.6% with topotecan, and DCR was 90.4% vs 60.2%, respectively. Investigator-assessed outcomes were reported as consistent with those seen in the central review.

Safety Findings

In terms of safety, grade 3 or higher treatment-related adverse events occurred at a 60.9% rate with Ris-Rez vs 78.2% with topotecan, with the most common grade 3 or higher treatment-related adverse events being hematologic, including decreases in neutrophil count (27.0% vs. 40.7%), white blood cell count (24.3% vs. 32.4%), lymphocyte count (16.1% vs. 10.2%), platelet count (13.9% vs. 59.7%), and anemia (17.4% vs. 25.0%) in the respective arms.

Ris-Rez is being evaluated in relapsed extensive-stage SCLC outside China in the global phase 3 trial, EMBOLD SCLC-301 (NCT07099898), with pivotal data anticipated in 2027.³

Ris-Rez is also being investigated in patients with relapsed osteosarcoma in the phase 3 ARTEMIS-011 trial (NCT06935409), where it improved PFS vs gemcitabine plus docetaxel.

REFERENCES

1. Wang J, Wang L, Duan J, et al. Risvutatug Rezetecan (a B7-H3-Directed ADC) versus topotecan in relapsed sclc: primary results of phase 3 ARTEMIS-008. Presented at: IASLC 2026 World Conference on Lung Cancer; September 12-15, 2026; Seoul, Republic of Korea. PL02.04.

2. Phase III ARTEMIS-008 Trial Shows Risvutatug Rezetecan Significantly Improves Overall Survival in Relapsed Small-Cell Lung Cancer. News release. International Association for the Study of Lung Cancer. September 13, 2026. Accessed September 13, 2026. https://tinyurl.com/4yd9udzk

3. GSK’s licensor Hansoh Pharma announces positive phase III results for Ris-Rez in China patient population. News release. GSK. July 10, 2026. Accessed September 14, 2026. https://tinyurl.com/4as9msmb