Roche and MediLink's Tam-Peli (Tambotatug Pelitecan) Delivers Landmark Phase 3 Overall Survival Win in Relapsed Small-Cell Lung Cancer
On September 13, 2026, Roche and its collaborator MediLink Therapeutics announced positive interim results from the randomized, open-label Phase III TAISHAN-302 trial (NCT06612151) evaluating the novel B7-H3-targeting antibody-drug conjugate (ADC) tambotatug pelitecan (Tam-Peli; YL201; RG6919). The trial met its primary endpoint of overall survival (OS) with statistical significance and clinical relevance, showing that Tam-Peli significantly improved OS, progression-free survival (PFS), and objective response rate (ORR) compared to the standard chemotherapy topotecan in patients with relapsed small-cell lung cancer (SCLC).
This result represents a historic milestone, as overall survival victories in relapsed SCLC are extremely rare and regulatorily meaningful, given that topotecan has remained the default second-line treatment for decades despite modest clinical benefit.
TAISHAN-302 Clinical Efficacy and Global Milestones
The TAISHAN-302 trial enrolled 451 patients whose SCLC had progressed after one prior line of platinum-based chemotherapy with or without a PD-L1 inhibitor. Patients were randomized to receive either Tam-Peli (2.0 mg/kg intravenously on Day 1 of each 21-day cycle, capped at 200 mg) or topotecan.
Interim analysis data presented at the International Association for the Study of Lung Cancer (IASLC) 2026 World Conference on Lung Cancer (WCLC) revealed that:
- Tam-Peli reduced the risk of death by 54% compared to topotecan.
- The therapy demonstrated a highly favorable and manageable safety profile.
This landmark Phase III success immediately translated into regulatory progress. On September 2, 2026, MediLink announced that the New Drug Application (NDA) for Tam-Peli was officially accepted by the Center for Drug Evaluation (CDE) of the China National Medical Products Administration (NMPA) for recurrent SCLC, and was proposed for priority review. This marks the first time globally that an ADC’s regulatory filing has been accepted for the SCLC indication based on Phase III clinical trial data.
Innovative TMALIN Platform and Broader Pipeline
Tam-Peli utilizes MediLink's proprietary TMALIN® (Tumor Microenvironment-Activatable Linker) platform. It links a B7-H3-specific monoclonal antibody to a novel topoisomerase 1 inhibitor payload with a drug-to-antibody ratio (DAR) of 8. The stable, hydrophilic linker and dual-release mechanism allow Tam-Peli to release its cytotoxic payload both intracellularly and extracellularly within the tumor microenvironment, maximizing therapeutic efficacy while minimizing off-target systemic toxicity.
B7-H3 is highly expressed across multiple solid tumors but is minimally present in healthy tissue. In addition to SCLC, Tam-Peli holds three FDA Orphan Drug Designations and has received five CDE Breakthrough Therapy Designations in China for other indications, including nasopharyngeal carcinoma, esophageal squamous cell carcinoma, and pancreatic cancer.