Roche announced that its collaborator MediLink Therapeutics has 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.
The study met its primary endpoint of overall survival. Tambotatug pelitecan reduced the risk of death by 54%, with median overall survival of 13.3 months compared with 9.4 months for topotecan (HR 0.46; 95% CI, 0.35–0.62; p<0.0001).
TAISHAN-302 Shows Improvements Across Key Efficacy Endpoints
Tambotatug pelitecan also significantly improved progression-free survival and objective response rate.
Median progression-free survival was 7.4 months with tambotatug pelitecan versus 2.8 months with topotecan, corresponding to a 71% reduction in the risk of disease progression or death (HR 0.29; 95% CI, 0.23–0.37; p<0.0001).
The confirmed objective response rate was 59.1% with tambotatug pelitecan compared with 9.7% with topotecan.
Consistent overall survival and progression-free survival benefits were observed across prespecified subgroups, including age, chemotherapy-free interval, and baseline liver or brain metastatic status.
Among patients with brain metastases at baseline, median intracranial progression-free survival was 6.1 months versus 4.2 months, while the intracranial response rate was 32.4% versus 2.9% in favor of tambotatug pelitecan.
Levi Garraway on the TAISHAN-302 Results
Levi Garraway, MD, PhD, Roche’s Chief Medical Officer and Head of Global Product Development, commenting on the findings, said:
“The second positive phase III trial for Tam-Peli, TAISHAN-302, reinforces our confidence in its potential to improve outcomes for people with cancer.”
He added:
“These data demonstrate clinically meaningful survival and response rate improvements in an aggressive and hard-to-treat disease, supporting our plans to initiate global phase III trials quickly.”
Safety Profile
Tambotatug pelitecan demonstrated lower rates of Grade 3 or higher treatment-related adverse events than topotecan, occurring in 46.4% versus 74.7% of patients.
Serious treatment-related adverse events occurred in 25.9% of patients receiving tambotatug pelitecan and 36.4% receiving topotecan.
Treatment-emergent interstitial lung disease or pneumonitis of any grade was reported in 4.9% versus 1.4% of patients, respectively. Grade 3 events occurred in 0.9% of patients in each group, with no Grade 4 or 5 cases reported.
About TAISHAN-302
TAISHAN-302 (NCT06612151) is a randomized, open-label Phase III trial involving 451 patients across 85 sites in China.
The trial evaluated tambotatug pelitecan at 2.0 mg/kg intravenously every 21 days against topotecan in patients with SCLC whose disease progressed after one previous line of platinum-based chemotherapy, with or without a PD-L1 inhibitor.
Overall survival was the primary endpoint, while key secondary endpoints included progression-free survival and objective response rate.
About Tambotatug Pelitecan
Tambotatug pelitecan is an investigational B7-H3-targeted antibody-drug conjugate based on MediLink Therapeutics’ TMALIN platform.
The therapy links a B7-H3-specific monoclonal antibody to a topoisomerase 1 inhibitor payload and uses a dual-release mechanism designed to deliver the cytotoxic payload both inside tumor cells and within the tumor microenvironment.
Following the positive Phase III TAISHAN-301 trial in nasopharyngeal carcinoma, TAISHAN-302 represents the second positive Phase III readout for tambotatug pelitecan.
Roche holds development, manufacturing, and commercialization rights for the therapy worldwide outside mainland China, Hong Kong, and Macau and plans to rapidly initiate global Phase III trials.
The TAISHAN-302 findings are being presented as a Late-Breaking Abstract during a Presidential Presentation at WCLC 2026 in Seoul, alongside simultaneous publication in The New England Journal of Medicine. China’s Center for Drug Evaluation has also accepted the New Drug Application for tambotatug pelitecan for filing.
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