abemaciclib + endocrine therapy + stereotactic radiosurgery

This combination treatment regimen is being evaluated by the H. Lee Moffitt Cancer Center and Research Institute for the management of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer that has spread to the brain. The regimen integrates **abemaciclib**, a selective small-molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), with standard-of-care **endocrine therapy** (such as fulvestrant or an aromatase inhibitor) and **stereotactic radiosurgery (SRS)**. Abemaciclib functions by inhibiting the phosphorylation of the retinoblastoma protein, which arrests the cell cycle in the G1 phase and prevents tumor cell proliferation. The endocrine therapy component targets the hormonal drivers of the cancer, while SRS provides localized, high-dose radiation to intact brain metastases or post-operative cavities to achieve local intracranial control. This multimodal approach aims to improve outcomes for patients with difficult-to-treat CNS involvement in breast cancer.

Other names

Abemaciclib and SRS in HR+/HER2- Breast Cancer Brain Metastasesabemaciclib + fulvestrant + stereotactic radiosurgeryabemaciclib + aromatase inhibitor + stereotactic radiosurgery