A decades-old ceiling in small cell lung cancer
Small cell lung cancer is aggressive: most patients respond to first-line chemotherapy, and most relapse within a year. For relapsed disease the main approved option worldwide has long been topotecan, a chemotherapy that extends survival only modestly and causes significant bone-marrow toxicity. Several drug classes have tried and failed to beat it.
At the presidential symposium of the 2026 World Conference on Lung Cancer in Seoul, on 13 September, Professor Wang Jie — director of the department of medical oncology at the Cancer Hospital, Chinese Academy of Medical Sciences — presented the interim analysis of ARTEMIS-008 as a late-breaking abstract: a randomised phase 3 trial of risvutatug rezetecan, an antibody-drug conjugate targeting B7-H3, against topotecan in relapsed small cell lung cancer.
What the trial found
The multicentre, randomised, open-label phase 3 trial enrolled patients whose disease had progressed during or after platinum chemotherapy. At a median follow-up of 12.2 months, the ADC met its primary endpoint: median overall survival was 18.5 months versus 10.3 months for topotecan, a hazard ratio of 0.46 with high statistical significance.
Median progression-free survival 7.2 versus 3.0 months (HR 0.33); objective response rate about 58% versus 12.6%; nearly 65% of patients alive beyond one year. Benefit was consistent across predefined subgroups, including platinum-sensitive and platinum-resistant disease and patients with brain metastases. Grade ≥3 treatment-related adverse events were lower in the ADC arm (60.9% vs 78.2%), mostly manageable blood-count effects, with no new safety signals.
The data are from a prespecified interim analysis of an open-label trial, and the reports reviewed do not disclose the randomised patient count, so the results should be read with those caveats. The sponsor, Hansoh Pharma, filed a marketing application with China's NMPA on 2 September 2026 for this indication, and a global phase 3 trial is roughly one-third enrolled. Overseas rights are held by GSK.
Why it matters
This is the first randomised phase 3 trial anywhere to show an overall survival benefit from a B7-H3-targeted therapy, in a cancer where second-line survival had barely moved in decades. It is also an example of the "developed in China, for the world" pattern: the pivotal evidence was generated in Chinese hospitals first. For patients, the drug is not yet on the market — approval is under review. This summary belongs to the Cancer & Tumors health area and is not treatment advice.