Risvutatug Rezetecan Improves Overall Survival in Relapsed SCLC Trial

Risvutatug rezetecan (Ris-Rez; HS-20093) significantly improved overall survival (OS) compared with topotecan (Hycamtin) in patients with advanced or relapsed small cell lung cancer (SCLC) in the phase 3 ARTEMIS-008 trial (NCT06498479), according to a news release from GSK.¹ The trial, conducted in patients in China by GSK’s licensor Hansoh Pharma, will support a planned regulatory submission in China.

What did ARTEMIS-008 show?

ARTEMIS-008 met its primary end point, with Ris-Rez demonstrating a statistically significant and clinically meaningful improvement in OS compared with standard-of-care topotecan. A consistent benefit was observed across key secondary end points, including progression-free survival (PFS).

The safety profile appeared to be consistent with prior Ris-Rez findings, and no new safety signals were identified.

“These results are an important milestone as the first positive phase 3 [OS] data for a B7-H3–targeted ADC in any tumor type,” said Hesham Abdullah, MD, MSc, senior vice president and global head of oncology research and development at GSK, in the press release.¹ “Together, with other data generated to date, they further support the potential of B7-H3 as a promising target across lung cancer and other solid tumors and reinforce our continued development of Ris-Rez to improve standard of care in areas of high unmet need.”

What is the ARTEMIS-008 trial design?

ARTEMIS-008 is a multicenter, randomized, open-label, phase 3 study evaluating Ris-Rez vs topotecan in patients with relapsed SCLC following platinum-based first-line chemotherapy.² Approximately 460 patients were planned for 1:1 randomization to Ris-Rez at 8.0 mg/kg intravenously on day 1 of each 21-day cycle or to topotecan, with treatment continuing until disease progression.

The primary end point is OS. The trial’s secondary end points include objective response rate, disease control rate, duration of response, PFS, and the incidence and grade of treatment-emergent adverse events, each assessed by blinded independent central review and investigators.

Eligible patients were 18 years or older with histologically or cytologically confirmed SCLC that progressed on or after a first-line platinum-based regimen, at least 1 measurable lesion per RECIST v1.1 criteria, and an ECOG performance status of 0 or 1. Having adequate organ function was another requirement for enrollment on the trial.

Those who had received prior B7-H3–targeted agents or a prior topoisomerase I inhibitor—including a topoisomerase I inhibitor ADC—or who had untreated or symptomatic brain metastases were ineligible. Patients were also ineligible for enrollment if they had complex SCLC or transformed SCLC, limited-stage SCLC at diagnosis, or clinically significant bleeding symptoms or significant bleeding tendency within 1 month of beginning treatment.

What is risvutatug rezetecan, and how is it being developed?

Ris-Rez is a novel investigational B7-H3–targeted ADC composed of a fully human anti-B7-H3 monoclonal antibody covalently linked to a topoisomerase inhibitor payload. B7-H3 is highly expressed in SCLC tumors, and most patients with extensive-stage SCLC relapse after initial therapy and have limited treatment options. Investigators are advancing the agent across studies in lung cancer, prostate cancer, and other solid tumors, including the global phase 3 EMBOLD SCLC-301 trial (NCT07099898) in relapsed extensive-stage SCLC, with pivotal data expected next year.

Ris-Rez has received regulatory designations including orphan drug designations from the FDA and Japan’s Ministry of Health, Labour and Welfare in SCLC and from the EMA in pulmonary neuroendocrine carcinoma; EMA Priority Medicines designation for relapsed or refractory extensive-stage SCLC; and FDA breakthrough therapy designations for relapsed or refractory extensive-stage SCLC and for relapsed or refractory osteosarcoma.

References

1. GSK’s licensor Hansoh Pharma announces positive phase III results for Ris-Rez in China patient population. News release. GSK plc. July 10, 2026. Accessed July 10, 2026. https://tinyurl.com/2bmnz24b
2. ARTEMIS-008: HS-20093 compared with topotecan in subjects with relapsed small cell lung cancer. ClinicalTrials.gov. Updated October 16, 2024. Accessed July 10, 2026. https://tinyurl.com/4rhc852b