SKB BIO (ASX: 06990) has announced that its Phase 3 clinical trial for the combination therapy of its core TROP2-targeting antibody-drug conjugate (ADC), sac-TMT (also known as SKB264/MK-2870), with Merck's anti-PD-1 monoclonal antibody, pembrolizumab, has successfully met its primary endpoint in a pre-specified interim analysis.
The trial, named OptiTROP-Lung06, evaluated the combination as a first-line treatment for patients with PD-L1-negative, locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC). An independent data monitoring committee confirmed that the study achieved its primary endpoint of progression-free survival (PFS).
This marks the first global Phase 3 study where an ADC combined with an immune checkpoint inhibitor has achieved its primary endpoint in the first-line treatment of driver gene-negative, PD-L1-negative non-squamous NSCLC.
The randomized, open-label, multi-center study compared the efficacy and safety of sac-TMT plus pembrolizumab against chemotherapy plus pembrolizumab. The interim analysis showed a statistically significant and clinically meaningful improvement in PFS for the sac-TMT combination arm compared to the chemotherapy arm, with a trend towards benefit also observed in overall survival (OS).
The safety profile of the sac-TMT combination was consistent with previous reports, with no new safety signals identified. The company plans to discuss these results with the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA).
This positive outcome follows another Phase 3 study, OptiTROP-Lung05, for PD-L1-positive NSCLC, which also met its primary endpoint. Based on that study, a supplemental new drug application has been submitted to the CDE. The Lung05 results were presented at the 2026 ASCO Annual Meeting and published in The Lancet.
The success of the Lung06 study extends the potential of the sac-TMT and immunotherapy combination to the PD-L1-negative patient population, providing clinical support for this strategy to cover a broader range of first-line NSCLC patients and potentially optimizing the treatment landscape.
As the company's core product, sac-TMT is a novel TROP2 ADC with proprietary intellectual property, targeting various advanced solid tumors including NSCLC, breast cancer, gastric cancer, and gynecological cancers. It utilizes a unique bifunctional linker and has a drug-to-antibody ratio of 7.4.
The drug works by specifically binding to TROP2 on tumor cells, being internalized, and releasing its payload, a topoisomerase I inhibitor, which causes DNA damage and cell death. The payload's membrane permeability also enables a bystander effect, killing neighboring tumor cells.
In May 2022, SKB BIO granted Merck exclusive rights to develop, manufacture, and commercialize sac-TMT outside of Greater China. To date, four indications for sac-TMT have been approved in China, including for triple-negative breast cancer and EGFR-mutated NSCLC, with the first two already included in the national reimbursement drug list.
Sac-TMT has also received six Breakthrough Therapy Designations from the NMPA and is the first TROP2 ADC globally approved for a lung cancer indication. A supplemental application for its use with pembrolizumab in first-line PD-L1-positive NSCLC is under priority review by the NMPA.
Currently, SKB BIO is conducting nine registrational studies in China, while Merck is sponsoring 17 ongoing global Phase 3 studies evaluating sac-TMT as a monotherapy or in combination with pembrolizumab or other anticancer agents for various cancers.
Comments