STCube Confirms Efficacy of BTN1A1-Targeted Therapy in Non-Small Cell Lung Cancer

STCube announced on August 18 that it will participate in the World Conference on Lung Cancer (WCLC 2025), which will be held in Barcelona, Spain, from September 6 to 9 (local time). At the conference, the company will present preclinical and clinical data confirming the efficacy of therapeutic strategies targeting BTN1A1 in non-small cell lung cancer (NSCLC).

At this conference, two research abstracts related to the BTN1A1-targeted antibody Nelmastobart have been accepted. The results are based on preclinical studies using patient-derived organoids (PDOs) from NSCLC patients and a retrospective analysis of data from a Phase 1 clinical trial.

The titles of the abstracts are: ▲ "Targeting BTN1A1 in PD-L1-Negative NSCLC: A Clinically Actionable Immune Checkpoint for Docetaxel-Based Combination Therapy," which explores the clinical utility of BTN1A1 as an immune checkpoint in docetaxel combination therapy for PD-L1-negative NSCLC; and ▲ "BTN1A1 and Nuclear YAP1 Co-Expression as Predictive Biomarkers for Nelmastobart Efficacy in Lung Cancer: Findings from a Phase 1 Trial," which investigates the co-expression of BTN1A1 and nuclear YAP1 as prognostic biomarkers in lung cancer.

The first abstract reports that, in NSCLC, BTN1A1 expression increases following chemotherapy with docetaxel, resulting in enhanced therapeutic response to Nelmastobart. STCube analyzed differential expression patterns of BTN1A1 and PD-L1 using patient-derived organoid models. The study confirmed that BTN1A1 expression specifically increased after docetaxel administration, and that the anti-BTN1A1 antibody showed a higher response rate than the anti-PD-L1 antibody.

Yoo Seunghan, Chief Scientific Officer (CSO) of STCube, stated, "The observed increase in BTN1A1 expression following chemotherapy suggests that therapies targeting BTN1A1 could be a promising strategy for PD-L1-negative NSCLC patients who do not respond to or have developed resistance to existing immunotherapies." He added, "These meaningful results confirm the clinical potential of BTN1A1-based combination strategies for the treatment of refractory NSCLC."

The second abstract presents analysis showing that co-expression of BTN1A1 and nuclear YAP1 correlates with the clinical efficacy of Nelmastobart. A comparative analysis of tissue samples from four lung cancer patients (three with small cell lung cancer and one with non-small cell lung cancer) who participated in the Phase 1 clinical trial revealed that patients who were BTN1A1-positive and had high nuclear YAP1 expression exhibited longer progression-free survival (PFS).

CSO Yoo commented, "In tissues with high BTN1A1 expression, the proportion of nuclear YAP1-positive cells was also higher, and patients with both biomarkers tended to experience suppressed cancer progression and extended progression-free survival." He further explained, "These data support the validity of STCube's ongoing biomarker-driven clinical strategy." He added, "We have confirmed the value of BTN1A1 as a prognostic biomarker for both colorectal and lung cancer, and based on this, we are increasing the commercial potential of Nelmastobart as a global first-in-class drug."

Since this year, STCube has actively begun biomarker selection clinical trials based on a precision-driven strategy. Currently, clinical trials for colorectal cancer are underway in patients with BTN1A1-positive expression, and preparations are also being made for subsequent clinical trials in lung cancer.

Nelmastobart is a first-in-class immune checkpoint inhibitor that specifically binds to the novel immune checkpoint protein BTN1A1. BTN1A1 is expressed mutually exclusively with PD-L1 and shows higher expression rates than PD-L1 in major solid tumors. Notably, because it is mainly expressed in dormant cancer cells and chemotherapy-resistant cancer cells, it is expected to become a new treatment option for patients who do not respond to or have developed resistance to existing standard therapies.

This content was produced with the assistance of AI translation services.