Dr. Anders on Abemaciclib in HR+ Breast Cancer With Brain Metastases

Carey Anders, MD, director, Brain and Spine Metastasis Program, Duke Cancer Institute, discussed the use of abemaciclib (Verzenio), a selective CDK4/6 inhibitor, in patients with hormone receptor—positive, HER2-negative metastatic brain cancer with brain metastases.

In the study, 52 patients were evaluated and had a median of 4 prior systemic therapies. Of the group, 75% had prior chemotherapies and 71% had endocrine therapy in the metastatic setting. Moreover, 50% had whole brain radiotherapy, 39% stereotactic radiosurgery, and 8% had surgical resection of their brain metastases. Despite most patients being heavily pretreated, 40% of the lesions were unirradiated, allowing researchers to see the full impact of the drug. Patients received 200 mg of abemaciclib orally twice daily.

Three patients had a confirmed intracranial response (5.8%), which did not meet the 11% stipulated protocol. However, the intracranial clinical benefit was 25%. Additionally, 38% of patients showed a decrease in the sum of their intracranial lesions. Median progression-free survival was 4.4 months (95% CI, 2.6-5.5).

Further abemaciclib studies are necessary to assess its potential as monotherapy and combination strategies to better control brain metastases in multiple diseases.