OREG-103

OREG-103 (also known by its research clone name BY40 and clinical code BMS-986358) is a monoclonal antibody designed to target and inhibit **CD39** (Ectonucleoside triphosphate diphosphohydrolase 1). CD39 is a cell-surface enzyme highly expressed on regulatory T cells (Tregs), certain tumor cells, and the tumor-associated stroma. It plays a critical role in the purinergic signaling pathway by hydrolyzing extracellular ATP (a pro-inflammatory molecule that promotes immune activation) into AMP, which is subsequently converted to immunosuppressive adenosine by CD73. By blocking the enzymatic activity of CD39, OREG-103 prevents the degradation of ATP and the accumulation of adenosine in the tumor microenvironment. This dual action helps to alleviate Treg-mediated immunosuppression and restores the cytotoxic activity of effector CD8+ T cells and NK cells. Originally developed by **Orega Biotech**, the program was licensed to **Bristol Myers Squibb** for clinical development in oncology.

Other names

anti-CD39 monoclonal antibodyanti-CD-39 monoclonal antibodyanti-CD 39 monoclonal antibodyanti-CD39 mAbanti-CD-39 mAbanti-CD 39 mAbclone BY40