Ris Rez cuts risk of death by 54% in Phase III relapsed small cell lung cancer trial

GSK has reported positive overall survival results from the Phase III ARTEMIS 008 trial of risvutatug rezetecan, known as Ris Rez, in patients with relapsed small cell lung cancer in China.

The study compared the B7 H3 targeted antibody drug conjugate with topotecan in patients whose disease had progressed following platinum based first line treatment.

Ris Rez reduced the risk of death by 54% compared with topotecan, meeting the primary endpoint of the study after a median follow up of 12.2 months.

Median overall survival reached 18.5 months among 230 patients treated with Ris Rez, compared with 10.3 months among 231 patients who received topotecan.

The hazard ratio for overall survival was 0.46, with a 95% confidence interval of 0.35 to 0.62 and a p value below 0.0001.

The findings were presented during a Presidential Symposium at the 2026 World Conference on Lung Cancer in Seoul, South Korea.

Results from ARTEMIS 008 represent the first Phase III data to demonstrate an overall survival benefit for a B7 H3 targeted antibody drug conjugate in any tumour type.

Hesham Abdullah, Senior Vice President and Global Head of Oncology Research and Development at GSK, said the findings add to the growing evidence supporting Ris Rez and strengthen the company’s lung cancer development programme.

He said the survival improvement, combined with the observed safety profile, provides further support for investigating Ris Rez in both later and earlier treatment settings for small cell lung cancer.

Benefits were also recorded across several secondary efficacy measures.

Independent review showed median progression free survival of 7.2 months with Ris Rez compared with 3.0 months for topotecan. The corresponding hazard ratio was 0.33, with a 95% confidence interval of 0.25 to 0.42.

The objective response rate assessed by independent review was 58.3% with Ris Rez, compared with 12.6% for topotecan.

Disease control rates were 90.4% and 60.2% respectively.

Ris Rez was also associated with a lower rate of severe treatment related adverse events than the comparator.

Grade 3 or higher treatment related adverse events occurred in 60.9% of patients receiving Ris Rez, compared with 78.2% of those treated with topotecan.

The most frequently reported severe treatment related events with Ris Rez included reductions in neutrophils, white blood cells, lymphocytes and platelets, as well as anaemia.

GSK said these haematological adverse events were manageable and consistent with effects already known for this class of treatment.

Jie Wang, MD, Chair of the Medical Oncology Department at the National Cancer Center of the Chinese Academy of Medical Sciences and Principal Investigator of ARTEMIS 008, said treatment options remain limited once small cell lung cancer relapses.

She said patients treated with Ris Rez lived substantially longer while experiencing fewer severe treatment related adverse events, suggesting the therapy could represent an important new option for this population.

GSK holds exclusive rights to develop and commercialise Ris Rez outside mainland China, Hong Kong, Macau and Taiwan through its licensing agreement with Hansoh Pharmaceutical Group.

The company is developing the therapy across a broader global programme covering lung cancer, prostate cancer and other solid tumours.

This includes the Phase III EMBOLD SCLC 301 study in relapsed extensive stage small cell lung cancer, with pivotal results expected next year.

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ADC, b7h3, cancer research, clinical trial, GSK, Hansoh Pharma, lung cancer, Oncology, pharma news, wclc2026