L-type amino acid transporter 1 (LAT1) is highly expressed in cancer cells and activated immune cells and has been shown to play a role in tumor proliferation as well as immune activation in autoimmune diseases. Our compounds have demonstrated the potential to serve as new therapeutic options in both oncology and autoimmune disease fields.

LAT1 has attracted significant interest from researchers worldwide. Leveraging the LAT1 gene patents held by our founder until 2019, we have been advancing clinical development globally from an early stage. Favorable results regarding efficacy and safety in humans have been observed, and we have delivered multiple oral presentations at the American Society of Clinical Oncology (ASCO). As a result, interest from the research community continues to grow, with investigators in Japan and abroad having approached the Company regarding potential collaborative research and development.

LAT1 belongs to the SLC transporter superfamily and is responsible for the uptake of large neutral amino acids that are essential for the growth and proliferation of cancer cells.

As cells become cancerous, LAT1 expression on the cell membrane is markedly upregulated, leading to increased amino acid uptake. LAT1 overexpression has been observed in a wide range of solid tumors, including biliary tract cancer, pancreatic cancer, and brain tumors, and is associated with lymph node metastasis, enhanced cell proliferation, angiogenesis, and shorter survival outcomes.

Within the tumor microenvironment, excessive LAT1-dependent uptake of specific amino acids by cancer cells depletes extracellular amino acids, thereby reducing the availability of metabolic substrates required for T-cell activation, differentiation, and functional maintenance. This leads to impaired T-cell proliferation, survival, and effector function, ultimately preventing T-cells from sustaining their intrinsic anti-tumor activity and promoting immune evasion. Accordingly, LAT1 inhibitors are suggested to provide dual therapeutic benefits: (1) directly suppressing tumor growth by restricting amino acid acquisition in cancer cells, and (2) potentially restoring the anti-tumor functions of immune cells by alleviating metabolic competition within the tumor microenvironment.

LAT1 inhibitors have demonstrated efficacy at the cellular and animal levels, and our Phase I/II clinical trials in Japan have further shown evidence of efficacy in patients with biliary tract cancer and colorectal cancer, supporting their clinical potential.

A growing body of research indicates that LAT1 may serve as a novel therapeutic target for certain autoimmune diseases. LAT1 regulates immune-cell proliferation and the release of pro-inflammatory cytokines through the mTOR pathway. Studies have shown that genetic suppression of LAT1 or administration of LAT1 inhibitors reduces cytokine production from hyperactivated immune cells.

Based on these findings, inhibition of LAT1 function may represent a new therapeutic approach for controlling excessive immune responses. In autoimmune diseases characterized by neuroinflammation, such as multiple sclerosis, LAT1 inhibition is expected to suppress inflammation and oxidative stress–induced neuronal damage, offering a promising strategy for the treatment of neuroinflammatory disorders.