Culmerciclib: First Approval.

Culmerciclib (®) is an oral, small molecule CDK2/4/6 inhibitor developed by Chia Tai Tianqing Pharmaceutical for the treatment of breast cancer. By simultaneously inhibiting CDK2, CDK4 and CDK6, culmerciclib may help overcome resistance mechanisms in HR+/HER2- breast cancer. The drug received its first approval in China on 9 December 2025 for use in combination with fulvestrant in adults with HR+/HER2- advanced or metastatic breast cancer whose disease has progressed after endocrine therapy. This article summarizes the milestones in the development of culmerciclib leading to this first approval.