CHENGDU, China, July 14, 2026
Kelun-Biotech has announced a major clinical milestone after its Phase III OptiTROP-Lung06 trial evaluating sacituzumab tirumotecan (sac-TMT, SKB264/MK-2870) in combination with KEYTRUDA® (pembrolizumab) successfully met its primary endpoint of progression-free survival (PFS) in patients with PD-L1-negative locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC). According to the Independent Data Monitoring Committee (IDMC), the investigational regimen demonstrated a statistically significant and clinically meaningful improvement in PFS compared with the current first-line standard-of-care regimen combining pembrolizumab with platinum-based chemotherapy. The study also showed a positive trend in overall survival (OS) while maintaining a manageable safety profile consistent with previous clinical findings. Importantly, this is reported as the world’s first Phase III study demonstrating that a TROP2-directed antibody-drug conjugate (ADC) combined with an immune checkpoint inhibitor has achieved its primary endpoint in the first-line treatment of PD-L1-negative, driver gene-negative non-squamous NSCLC, potentially reshaping the future treatment landscape for one of the most difficult-to-treat lung cancer populations.
Phase III Trial Demonstrates Superior First-Line Treatment Strategy
The OptiTROP-Lung06 study was designed as a randomized, open-label, multicenter Phase III clinical trial comparing sac-TMT plus pembrolizumab against the current standard regimen of pembrolizumab combined with pemetrexed and platinum-based chemotherapy in patients with PD-L1 tumor proportion scores below 1%. Results from the pre-specified interim analysis demonstrated that replacing conventional chemotherapy with the TROP2-targeted ADC significantly prolonged progression-free survival, while early overall survival findings also favored the investigational combination. Researchers reported that the treatment maintained a safety profile consistent with previous studies and revealed no new safety signals, supporting continued regulatory discussions with China’s National Medical Products Administration (NMPA) regarding potential label expansion. The positive outcome follows the company’s earlier success in the OptiTROP-Lung05 trial involving PD-L1-positive NSCLC, providing additional evidence that the ADC plus immunotherapy strategy may benefit a much broader first-line lung cancer population.
Sac-TMT Expands Precision Oncology Opportunities
Sacituzumab tirumotecan (sac-TMT) is a novel TROP2-directed antibody-drug conjugate engineered with a proprietary bifunctional linker that efficiently delivers a topoisomerase I inhibitor payload directly into tumor cells while also generating a bystander effect within the tumor microenvironment. The investigational therapy is currently being evaluated across multiple solid tumors, including lung cancer, breast cancer, gastric cancer, gynecological cancers, and genitourinary malignancies. The therapy has already secured four approved indications in China, including several treatments for advanced NSCLC and triple-negative breast cancer, while receiving six Breakthrough Therapy Designations from Chinese regulators. In addition, Merck & Co. (MSD) holds exclusive commercialization rights for sac-TMT outside Greater China and is currently conducting 17 global Phase III studies, highlighting growing international confidence in the therapy’s clinical potential and commercial value.
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Positive Results Reinforce Kelun-Biotech’s Global Oncology Leadership
The success of OptiTROP-Lung06 represents another significant achievement for Kelun-Biotech’s expanding oncology pipeline and strengthens the company’s position as a global innovator in antibody-drug conjugate (ADC) development. By demonstrating superior efficacy over the current chemotherapy-based standard of care, the combination of sac-TMT and pembrolizumab could establish a new first-line treatment option for patients with PD-L1-negative NSCLC, a population that has historically experienced limited long-term survival benefits. The findings also reinforce the growing role of ADC-based immunotherapy combinations in precision oncology and support future regulatory submissions and global commercialization efforts. As clinical development continues across multiple tumor types, Kelun-Biotech remains focused on expanding access to innovative targeted therapies that address significant unmet medical needs while advancing next-generation cancer treatment worldwide.
Source: Kelun-Biotech press release
