B7-H3–Targeted ADC Risvutatug Rezetecan Extends Survival in Small Cell Lung Cancer

A phase 3 trial conducted in China has shown that risvutatug rezetecan (Ris-Rez), an investigational antibody-drug conjugate (ADC) targeting B7-H3, significantly improved overall survival compared with topotecan in patients with advanced or relapsed small cell lung cancer (SCLC).¹

The trial, ARTEMIS-008² (NCT06498479), met its primary end point of overall survival, with a statistically significant and clinically meaningful improvement over topotecan, the current standard-of-care chemotherapy for relapsed SCLC. Consistent benefit was also observed on progression-free survival, a key secondary end point. The safety profile was consistent with earlier findings for the agent, and no new safety signals were identified.¹

Hansoh Pharma, the sponsor, plans to use the ARTEMIS-008 data to support a regulatory submission in China. GSK holds exclusive global development and commercialization rights to risvutatug rezetecan outside mainland China, Hong Kong, Macau, and Taiwan under a licensing agreement established in 2023.

First Survival Win for a B7-H3-Targeted ADC

According to GSK, licensee of Hansoh, the ARTEMIS-008 results represent the first positive phase 3 overall survival data reported for any B7-H3-targeted ADC in any tumor type. B7-H3 is a member of the B7 immune checkpoint family and is broadly expressed across several solid tumors, including SCLC, with limited expression in most normal tissues, making it an actively pursued ADC target.^3,4 Risvutatug rezetecan comprises a fully human anti–B7-H3 monoclonal antibody linked to a topoisomerase inhibitor payload.¹

"These results are an important milestone as the first positive phase 3 overall survival data for a B7-H3–targeted ADC in any tumour type. 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 tumours and reinforce our continued development of Ris-Rez to improve standard of care in areas of high unmet need,” said Hesham Abdullah, senior vice president, global head oncology, Research and Development, GSK, said in a news release.

Clinical Context

Relapsed extensive-stage SCLC remains an area of substantial unmet need. Most patients relapse after first-line therapy, and subsequent treatment options are limited, with poor prognosis and considerable treatment burden.^1,4 Topotecan has long served as a standard second-line option despite modest efficacy, underscoring interest in novel mechanisms such as B7-H3–directed ADCs.

Full efficacy and safety data from ARTEMIS-008, including specific survival and response figures, have not yet been publicly disclosed and are expected to be presented at an upcoming medical meeting.

Broader Development Program

Beyond ARTEMIS-008, GSK is evaluating risvutatug rezetecan globally across multiple tumor types, including lung and prostate cancers and other solid tumors. A global phase 3 trial, EMBOLD SCLC-301 (NCT07099898), is evaluating the agent in relapsed extensive-stage SCLC outside China, with pivotal data anticipated in 2027.¹

Risvutatug rezetecan has received several regulatory designations to date, including orphan drug designation from the US Food and Drug Administration (FDA) and Japan's Ministry of Health, Labour and Welfare for SCLC, and from the European Medicines Agency (EMA) for pulmonary neuroendocrine carcinoma, a category that includes SCLC.¹ It has also received EMA Priority Medicines (PRIME) designation for relapsed or refractory extensive-stage SCLC, and FDA breakthrough therapy designations for both relapsed or refractory extensive-stage SCLC and 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. July 10, 2026. Accessed July 14, 2026. https://tinyurl.com/4as9msmb

2. ARTEMIS-008:HS-20093 Compared With Topotecan in Subjects With Relapsed Small Cell Lung Cancer. ClinicalTrials.gov. Updated October 16, 2024. Accessed July 14, 2026. https://clinicaltrials.gov/study/NCT06498479

3. Altan M, Pelekanou V, Schalper KA, et al. B7-H3 expression in NSCLC and its association with B7-H4, PD-L1, and tumor-infiltrating lymphocytes. Clin Cancer Res. 2017;23(17):5202-5209. doi:10.1158/1078-0432.CCR-16-3107

4. Mountzios G, et al. Tarlatamab in small-cell lung cancer after platinum-based chemotherapy. N Engl J Med. 2025;393:349-361. doi:10.1056/NEJMoa2502099