Dr. Carey on the ​Results of the monarchE Trial in HR+/HER2- Breast Cancer

Lisa A. Carey, MD, FASCO, The Richardson and Marilyn Jacobs Preyer Distinguished Professor in Breast Cancer Research, deputy director of clinical sciences, division chief, Hematology and Oncology, University of North Carolina Lineberger Comprehensive Cancer Center, discusses the phase 3 monarchE trial in hormone receptor (HR)–positive, HER2-negative breast cancer.

HER2-positive breast cancer is an area of significant ongoing research, Carey says. The monarchE trial evaluated the CDK4/6 inhibitor abemaciclib (Verzenio) plus endocrine therapy in the adjuvant setting for patients with high-risk, early-stage, HR-positive, HER2-negative breast cancer. The study enrolled 5,637 patients. Eligible patients had to have 4 or more positive lymph nodes, or 1 to 3 positive nodes and either tumor size greater than 5 cm, histologic grade 3 disease, or central Ki-67 of at least 20%. 

Patients were randomized to receive adjuvant abemaciclib plus standard-of-care endocrine therapy for 2 years or endocrine therapy alone, Carey continues. At a median follow-up of 19 months, findings from the primary analysis demonstrated a 2-year invasive disease-free survival rate of 92.2% with the addition of abemaciclib vs 88.7% with endocrine therapy alone. However, longer follow-up is needed as the data remain immature, Carey concludes.