OQL051

OQL051 is a first-in-disease, oral, gut-restricted small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), developed for the prophylaxis of chemotherapy-induced diarrhea (CID) in patients receiving cytotoxic chemotherapies. The drug works by locally targeting cells of the digestive tract and transiently arresting rapidly dividing intestinal mucosal cells in the G1 phase of the cell cycle. This mechanism protects the intestinal lining from chemotherapy-induced damage without compromising systemic anti-tumor activity. Preclinical studies have shown that OQL051 achieves high concentrations in gastrointestinal tissues relative to plasma, supporting its gut-restricted action and minimizing interference with systemic chemotherapy regimens. The drug is being developed by OnQuality Pharmaceuticals and has received FDA clearance for an Investigational New Drug (IND) application to begin clinical trials for CID prevention[1][3][4][5][7].