Topotecan has been the default second-line chemotherapy for relapsed small-cell lung cancer for decades, and its survival benefit in that setting is modest at best. Against that backdrop, interim data from the randomized phase III TAISHAN-302 trial show that Tam-Peli (tambotatug pelitecan, YL201) cut the risk of death compared with topotecan in Chinese patients whose disease progressed after platinum-based chemotherapy, with or without a PD-L1 inhibitor. The trial hit its primary endpoint of overall survival, a result that matters because OS wins in this indication are rare and regulatorily meaningful.
The study enrolled 451 Chinese patients and tested Tam-Peli at 2.0 mg/kg intravenously on day one of each 21-day cycle, capped at 200 mg, against topotecan. That design mirrors the population and comparator most regulatory agencies would want to see for a second-line SCLC submission. The choice of topotecan as the control arm is notable: topotecan received FDA approval for relapsed SCLC based on data decades old, and lurbinectedin earned accelerated approval in June 2020 for the same platinum-pretreated population without a head-to-head OS comparison against topotecan. A statistically significant OS advantage over topotecan in a randomized phase III trial is a harder bar to clear than accelerated approval, which means this dataset, if it holds under full review, carries weight for a conventional approval pathway.
Tam-Peli is an anti-B7H3 antibody-drug conjugate, a target that also has active programs in prostate cancer: a phase II study in heavily pretreated metastatic castration-resistant prostate cancer showed antitumor activity as of late 2025. The SCLC readout is the more advanced dataset, and the OS result gives Roche and MediLink their clearest clinical validation yet for the molecule. Roche’s collaboration with MediLink positions it to potentially file in China on the strength of TAISHAN-302 data from a Chinese-only population, though whether that dataset supports a broader global filing will depend on how regulators outside China treat single-country phase III evidence.
The number to track from here is the hazard ratio for OS once full data are presented, likely at a major oncology congress. The width of the confidence interval and the magnitude of the survival separation will determine whether this result can anchor a registration package or whether a broader confirmatory study becomes necessary.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
