Dr. Williams on Selecting Between CDK4/6 Inhibitors in HR+/HER2- Breast Cancer

Nicole O. Williams, MD, assistant professor-clinical, director, BreastCARE Program, Cancer and Aging Resiliency Clinic, Division of Medical Oncology, The Ohio State University Comprehensive Cancer Center–James, discusses treatment considerations for selecting between CDK4/6 inhibitors in hormone receptor (HR)–positive, HER2-negative breast cancer.

Patients with HR-positive/HER2-negative disease who are started on endocrine therapy may have a CDK4/6 inhibitor added to their treatment, says Williams. Based on the findings from the MONALEESA-7 trial, ribociclib (Kisqali) should be considered for younger, premenopausal patients, Williams says. Abemaciclib (Verzenio) could be preferred for patients with central nervous system disease because some data suggest abemaciclib crosses the blood-brain barrier, Williams explains.

Notably, the adverse effect profiles of the 3 available CDK4/6 inhibitors may inform which agent is optimal for a given patient, says Williams. Patients with pancytopenia from bone marrow involvement may tolerate abemaciclib better compared with palbociclib (Ibrance) and ribociclib, which can cause additional myelosuppression. However, abemaciclib tends to cause more gastrointestinal toxicities compared with the other agents, Williams adds. Ultimately, it is important to discuss the safety profiles of the agents with each patient, concludes Williams.