Results from the randomised Phase III ARTEMIS-008 trial show that risvutatug rezetecan (Ris-Rez), a B7-H3-directed antibody-drug conjugate, significantly improved overall survival compared with topotecan in patients with relapsed small-cell lung cancer (SCLC) whose disease progressed on or after platinum-based chemotherapy.

The findings were presented today at the IASLC 2026 World Conference on Lung Cancer (WCLC).

ARTEMIS-008 (NCT06498479) is a multicenter, open-label, randomised Phase III study.

A total of 461 patients in China were randomised 1:1 to receive Ris-Rez 8.0 mg/kg every three weeks or topotecan 1.2 mg/m² on days 1 through 5 every three weeks.

More than 80% of patients had previously received PD-(L)1 inhibitors.

The primary endpoint was overall survival, with progression-free survival, objective response rate, disease control rate and safety among the key secondary endpoints.

At the June 6, 2026 data cutoff, after a median follow-up of 12.2 months, median overall survival was 18.5 months with Ris-Rez compared with 10.3 months with topotecan.

Ris-Rez reduced the risk of death by 54% (HR 0.46; 95% CI, 0.35–0.62; P<0.0001), with consistent overall survival benefits across relevant subgroups.

Blinded independent central review also favoured Ris-Rez across key secondary efficacy measures.

Median progression-free survival was 7.2 months with Ris-Rez versus 3.0 months with topotecan (HR 0.33; 95% CI, 0.25–0.42).

The objective response rate was 58.3% versus 12.6%, respectively, and the disease control rate was 90.4% versus 60.2%.

Investigator-assessed outcomes were consistent with the central review findings.

Grade 3 or higher treatment-related adverse events occurred less frequently with Ris-Rez than with topotecan, at 60.9% versus 78.2%.

The most common grade 3 or higher treatment-related adverse events were hematologic toxicities, including decreased neutrophil count, decreased white blood cell count, anaemia, decreased lymphocyte count and decreased platelet count.

“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 favourable safety profile,” said Professor Jie Wang, National Cancer Centre/National Clinical Research Centre for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences Peking Union Medical College, Beijing, China.

“These results suggest the potential of Ris-Rez to define a new standard of care in relapsed SCLC.”

Source: International Association for the Study of Lung Cancer