Dr. Meisel the Potential Utility of CDK4/6 Inhibitors in HER2+ Breast Cancer

Jane L. Meisel, MD, associate professor, Departments of Hematology and Medical Oncology and Gynecology & Obstetrics, Winship Cancer Institute, Emory University School of Medicine, discusses the potential utility of CDK4/6 inhibitors in HER2-positive metastatic breast cancer.

Some of the recent advances in HER2-positive metastatic breast cancer were made with HER2-targeted agents, says Meisel. However, 50% to 65% of patients with HER2-positive breast cancer have estrogen receptor (ER)–positive disease, Meisel explains. Patients with HER2-positive/ER-positive breast cancer comprise a heterogenous population that could require HER2-directed or endocrine therapy at various points within their disease course, Meisel explains.

As such, CDK4/6 inhibitors could have clinical utility in this patient population, says Meisel. For example, findings from the phase 2 monarcHER trial demonstrated improved progression-free survival with the combination of abemaciclib (Verzenio), fulvestrant (Faslodex), and trastuzumab (Herceptin) vs chemotherapy and trastuzumab alone in patients with hormone receptor (HR)–positive, HER2-positive advanced breast cancer. 

The ongoing phase 3 PATINA trial (NCT02947685) is evaluating palbociclib (Ibrance) plus HER2-directed therapy and endocrine therapy vs HER2-directed therapy and endocrine therapy alone as maintenance therapy for patients with HR-positive/HER2-positive metastatic breast cancer. Findings from the study could established CDK4/6 inhibitors as a maintenance therapy option for patients with HER2-positive disease, concludes Meisel.