Risvutatug Rezetecan Shows OS Benefit Over Topotecan in Relapsed SCLC

Risvutatug rezetecan (HS-20093; Ris-Rez) demonstrated statistically significant and clinically meaningful improvement in overall survival (OS) compared with topotecan in patients with advanced or relapsed small-cell lung cancer (SCLC), according to results from the pivotal phase 3 ARTEMIS-008 trial (NCT06498479).¹

Benefit was also consistent across key secondary end points, including progression-free survival.

These findings represent the first positive phase 3 OS data reported for a B7-H3-targeted antibody-drug conjugate (ADC) in any tumor type and will support a regulatory submission in China.

The agent has received multiple regulatory designations internationally, including FDA breakthrough therapy designation and EMA priority medicines designation for relapsed or refractory extensive-stage SCLC (ES-SCLC).

"These results are an important milestone as the first positive phase III overall survival data for a B7-H3-targeted ADC in any tumor 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 tumors and reinforce our continued development of Ris-Rez to improve standard of care in areas of high unmet need,” Hesham Abdullah, senior vice president and global head of Oncology, R&D, at GSK said in a news release.

How was the ARTEMIS-008 trial designed?

ARTEMIS-008 is a phase 3, randomized, open-label, multicenter study comparing HS-20093 with topotecan in patients at least 18 years of age from China with histologically or cytologically confirmed, limited-stage or ES-SCLC that had disease progression on or after a first-line, platinum-based regimen.²

Eligible patients were randomly assigned 1:1 to receive HS-20093 as an intravenous infusion at a dose of 8.0 mg/kg on day 1 of each 21-day cycle or topotecan until disease progression.

The study’s primary end point was OS; secondary end points included PFS, overall response rate, disease control rate, duration of response and safety.

What additional data have been reported with Ris-Rez in lung cancer and sarcoma?

Ris-res previously demonstrated encouraging early efficacy and a manageable safety profile when administered alongside the PD-L1 inhibitor adebrelimab in pretreated patients with advanced nonsquamous non–small cell lung cancer without actionable genomic alterations, according to data from the expansion cohort of the phase 1 ARTEMIS-101 trial (NCT05276609) presented at the 2026 American Association for Cancer Research Annual Meeting.³

Based on data from this study, the agent was granted orphan drug designation (ODD) in SCLC by the FDA in December 2025, as well as Japan's Ministry of Health, Labour and Welfare in March 2026.⁴ Of note, ODD was also granted to Ris-Rez in pulmonary neuroendocrine carcinoma by the EMA in October 2025.⁵

Additionally, updated findings from the phase 2 ARTEMIS-002 trial (NCT05830123) showed antitumor activity and manageable safety with Ris-Rez in heavily pretreated patients with relapsed/refractory osteosarcoma and soft tissue sarcoma.⁶ The FDA granted breakthrough therapy designation to the agent to the agent for patients with relapsed/refractory osteosarcoma whose disease has progressed on at least 2 prior lines of therapy in January 2025 based on previously reported data from the trial.⁷

What’s next for Ris-Rez development in the global sphere?

According to the news release, GSK is advancing a global phase 3 program for Ris-Rez outside China through the multicenter, randomized, open-label EMBOLD SCLC-301 trial (NCT07099898), which is evaluating Ris-Rez in relapsed ES-SCLC.⁸ The study is ongoing, and the expected completion date is in 2027.

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 10, 2026.https://www.gsk.com/en-gb/media/press-releases/gsk-s-licensor-hansoh-pharma-announces-positive-phase-iii-results-for-ris-rez-in-china-patient-population/
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://clinicaltrials.gov/study/NCT06498479
3. Zhong R, Liu H, Zheng W, et al. Combination of risvutatug rezetecan and adebrelimab in previously treated advanced nsq-NSCLC without actionable genomic alterations: results from ARTEMIS-101, a phase 1 study. Cancer Res. 2026;86(suppl 8):CT038. doi:10.1158/1538-7445.AM2026-CT038
4. GSK’227, a B7-H3-targeted antibody-drug conjugate, granted orphan drug designation in small-cell lung cancer by the US FDA. News release. GSK. December 10, 2025. Accessed July 10, 2026. https://www.gsk.com/en-gb/media/press-releases/gsk-227-a-b7-h3-targeted-antibody-drug-conjugate-granted-orphan-drug-designation-in-small-cell-lung-cancer-by-the-us-fda/
5. GSK's B7-H3-targeted antibody-drug conjugate, GSK'227, receives Orphan Drug Designation in the EU. News Release. GSK. October 28, 2025. Accessed July 10, 2026. https://www.gsk.com/en-gb/media/press-releases/gsk-s-b7-h3-targeted-antibody-drug-conjugate-gsk-227-receives-orphan-drug-designation-in-the-eu/
6. Xie L, Shen J, Xu J, et al. ARTEMIS-002: a phase II study of HS-20093 in patients with relapsed or refractory sarcomas. Ann Oncol. 2025;36(suppl 2):S1337. doi:10.1016/j.annonc.2025.08.3295
7. GSK’s B7-H3-targeted antibody-drug conjugate, GSK’227, receives US FDA breakthrough therapy designation in late-line relapsed or refractory osteosarcoma. News release. GSK. January 7, 2025. Accessed July 10, 2026. https://www.gsk.com/en-gb/media/press-releases/gsk-b7-h3-targeted-antibody-drug-conjugate-gsk227-receives-us-fda-breakthrough-therapy-designation-in-late-line-relapsed-or-refractory-osteosarcoma/
8. A study of GSK5764227 in participants with relapsed small cell lung cancer (SCLC). Clinicaltrials.gov. Updated May 27, 2026. Accessed July 10, 2026. https://clinicaltrials.gov/study/NCT07099898