BGP-31609

**BGP-31609** is a first-in-class covalent small molecule inhibitor of PAX8 (paired box 8), a transcription factor historically considered undruggable and overexpressed in ovarian and other cancers. Developed by **BridGene Biosciences** using their proprietary IMTAC™ chemoproteomics platform, it binds irreversibly to a cysteine residue in PAX8's DNA-binding domain, disrupting DNA binding, transcriptional activity, and expression of downstream oncogenic targets like FGF18 and CCNA2. In preclinical assays, it demonstrates dose-dependent inhibition of PAX8-driven luciferase activity, selective antiproliferative effects in PAX8-high ovarian cancer cells (e.g., OVCAR3), and sparing of PAX8-negative cells (e.g., A549), with minimal off-target activity[1][2][3].