Tambotatug Pelitecan Improves Overall Survival in Relapsed Small-Cell Lung Cancer
Roche announced that its collaborator MediLink Therapeutics reported positive interim results from the Phase III TAISHAN-302 trial, evaluating tambotatug pelitecan (YL201) versus topotecan in Chinese patients with relapsed small-cell lung cancer (SCLC) following prior platinum-based chemotherapy with or without a PD-L1 inhibitor, according to data presented. The study met its primary endpoint of overall survival in this aggressive malignancy, demonstrating a significant reduction in the risk of death compared to topotecan.
- Tambotatug pelitecan reduced the risk of death by 54% compared to topotecan, yielding a median overall survival of 13.3 months versus 9.4 months (HR 0.46; 95% CI, 0.35–0.62; p<0.0001).
- The investigational antibody-drug conjugate lowered the risk of disease progression or death by 71%, with a median progression-free survival of 7.4 months against 2.8 months for topotecan (HR 0.29; 95% CI, 0.23–0.37; p<0.0001).
- Grade 3 or higher treatment-related adverse events occurred in 46.4% of patients receiving tambotatug pelitecan, compared to 74.7% in the topotecan arm.
Clinical Efficacy and Survival Outcomes in TAISHAN-302
The randomized, open-label Phase III trial (NCT06612151) enrolled 451 patients across 85 sites in China to evaluate tambotatug pelitecan administered at 2.0 mg/kg intravenously every 21 days. According to findings published ahead of print in the New England Journal of Medicine and discussed as a Late-Breaking Abstract during a Presidential Presentation at WCLC 2026 in Seoul, the therapy achieved a confirmed objective response rate of 59.1%, compared with 9.7% for the topotecan cohort. Consistent survival benefits extended across prespecified subgroups defined by age, chemotherapy-free interval, and baseline liver or brain metastatic status. For patients presenting with brain metastases, median intracranial progression-free survival reached 6.1 months versus 4.2 months, while the intracranial response rate stood at 32.4% compared to 2.9% favoring the investigational agent.
Levi Garraway, MD, PhD, Roche’s Chief Medical Officer and Head of Global Product Development, noted that the data demonstrate clinically meaningful survival and response rate improvements in a hard-to-treat disease. These findings reinforce confidence in the molecule and support plans to initiate global Phase III trials quickly, according to statements released by Roche.
Safety Profile and Mechanism of Action
Tambotatug pelitecan is a B7-H3-targeted antibody-drug conjugate developed from MediLink Therapeutics’ TMALIN platform. The therapy pairs a B7-H3-specific monoclonal antibody with a topoisomerase 1 inhibitor payload, utilizing a dual-release mechanism designed to deploy the cytotoxic payload both inside tumor cells and within the surrounding tumor microenvironment. Regarding safety, serious treatment-related adverse events were reported in 25.9% of patients in the experimental arm versus 36.4% in the control arm. Treatment-emergent interstitial lung disease or pneumonitis of any grade occurred in 4.9% of patients receiving tambotatug pelitecan and 1.4% of those receiving topotecan, with Grade 3 events occurring in 0.9% of participants in both groups and no Grade 4 or 5 cases recorded.
This readout represents the second positive Phase III trial for the molecule, following previous evaluations in nasopharyngeal carcinoma. Roche holds global development, manufacturing, and commercialization rights for tambotatug pelitecan outside mainland China, Hong Kong, and Macau.
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