CDK2 inhibitor BLU-222 synergizes with CDK4/6 inhibitors in drug resistant breast cancers through p21/p27 induction.

ABSTRACT: Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) combined with endocrine therapy are the standard first-line treatment for hormone receptor-positive, HER2-negative (HR+/HER2-) metastatic breast cancer, but resistance inevitably develops. In triple-negative breast cancer (TNBC), the efficacy of CDK4/6i remains uncertain. Our study shows that the selective CDK2 inhibitor BLU-222, while effective alone, enhances synergistic activity when combined with CDK4/6i in resistant HR+/HER2- and TNBC models, leading to increased apoptosis and cell cycle arrest. In vivo, combining BLU-222 with palbociclib or ribociclib produced significant antitumor activity across eight resistant models, driving durable tumor regression and prolonged survival. Mechanistically, BLU-222, alone or with palbociclib, upregu

SUBMITTER: Luo L 

PROVIDER: S-EPMC12828054 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature