DA-4505

DA-4505 is an orally bioavailable, potent, and selective small molecule inhibitor of the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor involved in regulating innate and adaptive immunity. Activation of AhR by tryptophan metabolites such as kynurenine contributes to immunosuppression within the tumor microenvironment by inhibiting T lymphocyte, macrophage, and dendritic cell activity. DA-4505 antagonizes AhR to counteract these effects, thereby enhancing anti-tumor immune responses. Preclinical studies have shown that DA-4505 demonstrates antitumor efficacy both as a single agent and in combination with PD-1 inhibitors like pembrolizumab, suggesting potential for overcoming resistance to immune checkpoint blockade therapies in solid tumors. The drug is being developed primarily for advanced solid tumors including non-small cell lung cancer (NSCLC), colorectal cancer (microsatellite stable), urothelial carcinoma, and head and neck squamous cell carcinoma[1][2][3][4][5][6].