Tam-Peli cuts SCLC death risk 54% in Phase III, Roche reports
Roche and its Chinese collaborator MediLink Therapeutics have reported phase III data showing tambotatug pelitecan (Tam-Peli) reduced the risk of death by 54% compared with topotecan in patients with relapsed small-cell lung cancer, with the results published simultaneously in the New England Journal of Medicine and presented as a late-breaking abstract at the IASLC World Conference on Lung Cancer in Seoul.
The TAISHAN-302 trial enrolled 451 patients across 85 sites in China, all of whom had progressed after one prior line of platinum-based chemotherapy with or without a PD-L1 inhibitor. Tam-Peli met its primary endpoint of overall survival with a median OS of 13.3 months versus 9.4 months for topotecan (stratified HR 0.46; 95% CI 0.35–0.62; p less than 0.0001). Secondary endpoints were equally striking: median progression-free survival extended to 7.4 months from 2.8 months, and the confirmed objective response rate was 59.1% against 9.7% for the standard-of-care comparator.
Trial design and safety
Efficacy improvements were consistent across prespecified subgroups, including patients with baseline brain metastases, where Tam-Peli extended median intracranial PFS to 6.1 months versus 4.2 months and achieved an intracranial response rate of 32.4% against 2.9%. The safety profile favoured Tam-Peli over topotecan: grade 3 or worse treatment-related adverse events occurred in 46.4% of patients on Tam-Peli compared with 74.7% on topotecan. Treatment-emergent interstitial lung disease across all grades was reported in 4.9% of Tam-Peli patients, a signal that will warrant monitoring in subsequent global studies, though no grade 4 or 5 events were recorded in either arm.
Tam-Peli is built on MediLink's proprietary TMALIN platform, which uses a stable, hydrophilic linker and a dual-release mechanism to deliver a topoisomerase 1 inhibitor payload both inside tumour cells and within the tumour microenvironment. The drug targets B7-H3, a protein broadly expressed across solid tumours but present at low levels in healthy tissue. Roche describes the approach as designed to maximise antitumour activity while limiting systemic toxicity, a claim the reported safety data broadly supports, though longer follow-up will be needed to characterise the ILD signal more fully.
Market context and competitive position
TAISHAN-302 is the second positive phase III readout for Tam-Peli, following the TAISHAN-301 trial in nasopharyngeal carcinoma. Roche licensed the asset from MediLink in January 2026, acquiring development, manufacturing, and commercialisation rights outside mainland China, Hong Kong, and Macau. China's NMPA has accepted the NDA for relapsed SCLC. Roche holds US FDA and China CDE Breakthrough Therapy Designations for the indication and has stated plans to initiate global phase III trials rapidly.
The relapsed SCLC landscape has long been difficult ground. Topotecan has remained a de facto standard of care despite modest survival benefit and significant toxicity, and the field has not seen a broadly adopted second-line successor. Lurbinectedin received FDA accelerated approval in 2020 but has not displaced topotecan universally, and no ADC has yet reached approval in this indication. Tam-Peli's data place it in a competitive position relative to both, with the magnitude of the OS and ORR benefit likely to attract substantial clinical and commercial interest as global trial sites open. The B7-H3 target is also being pursued by a number of other companies in solid tumours more broadly, so the field around this mechanism is developing quickly and the competitive landscape outside SCLC will bear watching.
Roche chief medical officer Levi Garraway said the 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."