CDK4/6 Inhibitors in Metastatic Breast Cancer: Approvals and Clinical Considerations

This episode, titled CDK4/6 Inhibitors in Metastatic Breast Cancer: Approvals and Clinical Considerations, features breast cancer panelists discussing the following critical questions:

What are the FDA-approved CDK4/6 inhibitors for metastatic breast cancer and please describe the clinical studies that led to their approval?

Can CDK4/6 inhibitors be used in patients with visceral crisis?

Led by the moderator, the panelists examined the three CDK4/6 inhibitors for the treatment of metastatic breast cancer: Palbociclib, Ribociclib, and Abemaciclib. Each approval was supported by pivotal phase 3 clinical trials demonstrating significant improvements in progression-free survival and overall response rates when combined with endocrine therapy. Palbociclib was evaluated in the PALOMA trials, Ribociclib in the MONALEESA series, and Abemaciclib in the MONARCH studies, all showing consistent benefit in hormone receptor–positive, HER2-negative metastatic breast cancer. These studies established the safety and efficacy profile of CDK4/6 inhibitors, including manageable hematologic and gastrointestinal adverse events. Regarding patients with visceral crisis, data are limited, and the use of CDK4/6 inhibitors in this high-risk population remains cautious and individualized. Clinicians may consider rapid-acting systemic therapy, often chemotherapy, in visceral crisis, but emerging evidence and clinical ex

Throughout the conversation, the experts provide a comprehensive reflection on the field and the factors that may shape how clinicians approach care moving forward.

In the next episode, Optimizing CDK4/6 Inhibitor Use: Dosing, Safety, and Pharmacist Management, panelists will continue their discussion and highlight the differences in dosing schedules among the three FDA-approved CDK4/6 inhibitors and how these variations may influence patient adherence. Faculty also discuss the distinct adverse event profiles of each agent and explored the critical role of pharmacists in monitoring, managing side effects, and leveraging electronic health records to optimize therapy and patient outcomes.