monarchE Investigators Set Out to Make Practice-Changing Impact in Breast Cancer

Nadia Harbeck, MD, PhD, discusses how the monarchE trial, which evaluated the efficacy of endocrine therapy with or without abemaciclib, will change breast cancer treatment.

Nadia Harbeck, MD, PhD, the head of the Breast Center at the European Society of Medial Oncology and the chair of the Conservative Oncology Department at the University of Munich, discusses how the monarchE trial, which evaluated the efficacy of endocrine therapy with or without abemaciclib (Verzenio), will change breast cancer treatment.

According to Harbeck, the monarchE trial is the first study to look at centralized prospective Ki-67 measures with a cut off at 20%. The study accomplished 2 things. First, it validated Ki-67 as a prognostic biomarker, even in clinically high-risk patients. Secondly, it showed the benefit of abemaciclib versus endocrine therapy alone in both Ki-67-high and Ki-67-low tumors, showing that the benefit of the agent was independent of levels.

Additionally, monarchE found that in clinically high-risk Ki-67-low tumors, better outcomes were seen in both arms. According to Harbeck, the findings warrants further follow-up investigation.