BLU-222

BLU-222 is an investigational, oral, potent, and highly selective small molecule inhibitor of cyclin-dependent kinase 2 (CDK2). It is being developed by Blueprint Medicines for the treatment of advanced solid tumors, with a particular focus on hormone receptor-positive (HR+), HER2-negative breast cancer. BLU-222 acts by inhibiting CDK2, a key regulator of the cell cycle that becomes hyperactivated in certain cancers—especially those with CCNE1 amplification or resistance to CDK4/6 inhibitors. Preclinical and early clinical data show that BLU-222 can modulate cell cycle pathways and demonstrate antitumor activity both as monotherapy and in combination with other agents such as ribociclib (a CDK4/6 inhibitor) and fulvestrant (an estrogen receptor antagonist). The drug is currently undergoing phase 1/2 clinical trials for various advanced solid tumors including breast, ovarian, endometrial, uterine, gastric cancers, esophageal adenocarcinoma, carcinosarcoma, and tumors harboring CCNE1 amplification[1][3][5][7].