• As a head-to-head Phase III trial comparing sac-TMT plus pembrolizumab with the first-line standard of care (immunotherapy plus chemotherapy), OptiTROP-Lung06 demonstrated the superiority of replacing conventional pemetrexed/platinum chemotherapy with sac-TMT, with significantly prolonged PFS and a positive OS trend compared with pembrolizumab plus pemetrexed and platinum-based chemotherapy.
• Focusing on the particularly challenging first-line treatment for PD-L1-negative non-squamous NSCLC population, the introduction of a TROP2 ADC to a PD-1 mAb not only delivers ADC's precise targeting and killing of tumor cells, but also activates the immune microenvironment through their synergetic mechanisms. This strategy is expected to unlock the therapeutic potential of the PD-1 mAb in patients with PD-L1-negative or limited immune responses, breaking this therapeutic bottleneck.
• Following the meeting of the primary endpoint in the Phase III OptiTROP-Lung05 study for first-line PD-L1-positive NSCLC, the positive results were achieved in another Phase III trial of sac-TMT plus pembrolizumab, providing robust clinical evidence supporting the expansion of this combination regimen to a broader first-line NSCLC population.

Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced  that the Independent Data Monitoring Committee (IDMC) concluded that the Phase III clinical study (OptiTROP-Lung06) of its trophoblast cell-surface antigen 2 (TROP2)-directed antibody drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®), in combination with MSD's^[1] anti-programmed cell death protein 1 (PD-1) therapy KEYTRUDA^®[2] (pembrolizumab) as a first-line treatment for programmed death-ligand 1 (PD-L1)-negative locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) has met its primary endpoint of progression‑free survival (PFS) at a prespecified interim analysis. This is the world's first Phase III clinical study of an ADC combined with an immune checkpoint inhibitor to meet its primary endpoint in the first-line treatment of driver gene‑negative and PD‑L1‑negative non-squamous NSCLC.

OptiTROP-Lung06 is a randomized, open‑label, multicenter Phase III clinical study evaluating the efficacy and safety of sac-TMT in combination with pembrolizumab versus chemotherapy in combination with pembrolizumab as first-line treatment for patients with locally advanced or metastatic non-squamous NSCLC who have PD-L1 tumor proportion score (TPS) <1%. The primary endpoint of the study was PFS assessed by blinded independent central review (BICR); secondary endpoints included overall survival (OS), safety and others. At a pre-specified interim analysis, the sac-TMT combined with pembrolizumab demonstrated a statistically significant and clinically meaningful improvement in PFS compared with pembrolizumab combined with pemetrexed and platinum-based chemotherapy, and a positive trend in OS was also observed. The safety profile of sac-TMT combined with pembrolizumab was consistent with that observed in previously reported studies, and no new safety signals were observed. The Company plans to communicate with the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China based on the results of this sac‑TMT study.

Previously, the Phase III registrational OptiTROP-Lung05 study of sac-TMT in combination with pembrolizumab as first-line treatment for PD-L1-positive NSCLC had successfully met its primary endpoint, supporting the submission of a new indication application to the CDE. The findings of the OptiTROP-Lung05 study were presented as an oral report at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting and simultaneously published in The Lancet. The positive results from the OptiTROP-Lung06 study mark the further expansion of sac-TMT plus immunotherapy into the PD-L1-negative population in first-line non-squamous NSCLC, providing clinical support for this combination strategy to cover a broader first-line NSCLC population and are expected to drive the optimization of first-line treatment landscape for driver gene-negative non-squamous NSCLC.

Professor Caicun Zhou, National Lead Principal Investigator from Shanghai East Hospital, Tongji University, said: "For patients with driver gene‑negative and PD‑L1‑negative NSCLC, immunotherapy combined with chemotherapy remains the current standard first-line treatment and has improved patient outcomes to some extent. However, long-term survival benefit remains limited. The achievement of positive results in the Phase III OptiTROP-Lung06 study represents an important breakthrough in the first-line treatment of PD-L1-negative NSCLC. These results not only provide robust clinical evidence supporting the 'ADC plus immunotherapy' strategy of sac-TMT in combination with pembrolizumab, but also have the potential to offer these patients a new first-line treatment option beyond the current standard of care, with the promise of improved survival outcomes."

Dr. Michael GE, CEO of Kelun-Biotech, stated: "We are delighted to see that sac-TMT combined with pembrolizumab has achieved exciting positive results compared with immunotherapy plus chemotherapy in the first-line treatment of patients with PD-L1-negative NSCLC. This ADC plus immunotherapy regimen has previously demonstrated superior efficacy over immunotherapy monotherapy in patients with PD-L1-positive NSCLC. The positive results of both the OptiTROP-Lung05 and OptiTROP-Lung06 studies confirm the strong synergetic effect of sac-TMT combined with pembrolizumab, supporting the potential of this combination regimen to benefit the broad first-line NSCLC population and bringing new treatment opportunities to patients with different PD-L1 expression levels."

Sac-TMT is currently being evaluated in ten registrational studies in lung cancer, including five registrational studies in China and five global multicenter Phase III studies.