Roche said on 13 September 2026 that its collaborator MediLink Therapeutics reported interim results from the randomised, open-label phase III TAISHAN-302 trial of tambotatug pelitecan, known as Tam-Peli or YL201, versus topotecan in Chinese patients with relapsed small-cell lung cancer who had progressed after platinum-based chemotherapy, with or without a PD-L1 inhibitor. Tam-Peli was administered at 2.0 mg/kg intravenously on day 1 of each 21-day cycle, with a maximum dose of 200 mg.
The trial met its primary overall survival endpoint. Tam-Peli reduced the risk of death by 54%, with median overall survival of 13.3 months versus 9.4 months for topotecan (stratified hazard ratio 0.46; 95% CI 0.35-0.62; p<0.0001). Progression-free survival was also significantly longer, at a median 7.4 months versus 2.8 months (HR 0.29; 95% CI 0.23-0.37; p<0.0001). The confirmed objective response rate was 59.1% for Tam-Peli versus 9.7% for topotecan. Key secondary endpoints included investigator-assessed PFS, ORR, disease control rate, duration of response, time to response, safety, pharmacokinetics and immunogenicity.
The study enrolled 451 patients across 85 sites in China, with 225 assigned to Tam-Peli and 226 to topotecan. Results were consistent across prespecified subgroups, including age, chemotherapy-free interval and baseline liver or brain metastases. In patients with baseline brain metastases, median intracranial progression-free survival was 6.1 months versus 4.2 months (unstratified HR 0.43; 95% CI 0.27-0.68), and the intracranial response rate was 32.4% versus 2.9%.
Safety data showed lower rates of grade 3 or higher treatment-related adverse events with Tam-Peli than with topotecan, at 46.4% versus 74.7%. Serious treatment-related adverse events occurred in 25.9% of patients receiving Tam-Peli versus 36.4% on topotecan. Treatment-emergent interstitial lung disease or pneumonitis of any grade occurred in 4.9% of Tam-Peli patients versus 1.4% on topotecan; grade 3 events were 0.9% in each group, with no grade 4 or 5 events reported.
The data are being presented as a late-breaking abstract at the International Association for the Study of Lung Cancer 2026 World Conference on Lung Cancer in Seoul and published in The New England Journal of Medicine. The Center for Drug Evaluation of China's National Medical Products Administration has accepted the new drug application for filing.
Tam-Peli is an investigational antibody-drug conjugate targeting B7-H3, a protein broadly expressed in solid tumours but limited in normal tissue. It is built on MediLink's TMALIN platform and links a B7-H3-specific monoclonal antibody to a topoisomerase 1 inhibitor payload with a drug-to-antibody ratio of 8. Its stable linker and dual-release mechanism are designed to deliver the payload inside tumour cells and in the tumour microenvironment.
Under the collaboration and exclusive licensing agreement, Roche holds development, manufacturing and commercialisation rights for Tam-Peli worldwide outside mainland China, Hong Kong and Macau. The company said it is advancing clinical development across multiple solid tumour types and plans to rapidly initiate global phase III trials. The result follows the positive phase III TAISHAN-301 trial in nasopharyngeal carcinoma.
Tam-Peli has received U.S. FDA and China CDE Breakthrough Therapy Designations for relapsed small-cell lung cancer. Beyond that indication, it holds two FDA Orphan Drug Designations and three CDE Breakthrough Therapy Designations across nasopharyngeal carcinoma, esophageal squamous cell carcinoma and pancreatic cancer.
Roche's Chief Medical Officer Levi Garraway said the second positive phase III trial for Tam-Peli reinforced confidence in its potential to improve outcomes in an aggressive disease and supported plans to start global phase III trials quickly.
Lung cancer remains the leading cause of cancer-related deaths worldwide, with about 1.8 million deaths annually. Small-cell lung cancer accounts for 15% of lung cancer diagnoses and is highly aggressive, with poor outcomes for many patients with recurrent disease.
