MonarchE trial

12 July 2018



To evaluate whether the combination of abemaciclib (an experimental drug) plus standard endocrine/hormonal therapy improves outcomes in women or men with hormone receptor positive (HR+) & human epidermal receptor 2 negative (HER2 -) high risk breast cancer compared to endocrine therapy alone.

Scientific Title

MonarchE: Protocol I3Y-MC-JPCF A Randomized, Open-Label, Phase 3 Study of Abemaciclib Combined with Standard Adjuvant Endocrine Therapy versus Standard Adjuvant Endocrine Therapy Alone in Patients with High Risk, Node Positive, Early Stage, Hormone Receptor Positive, Human Epidermal Receptor 2 Negative, Breast Cancer


Breast cancer is the most frequently diagnosed cancer among women and is a major cause of cancer-related deaths worldwide. The most prevalent sub-type of breast cancer is hormone receptor-positive (HR positive), human epidermal growth factor receptor 2-negative (HER2 negative) breast cancer and accounts for 70% of all breast cancers.

Approximately 90% of breast cancer patients are diagnosed at an early stage of their disease. With current standard of care hormonal/endocrine therapy and chemotherapy, approximately 30% of HR positive breast cancer patients who are initially diagnosed at early stage, experience distant relapse with metastases (spread of the cancer from the primary site to other parts of the body). Thus, there is a critical need to improve the absolute benefit of adjuvant endocrine therapy for HR positive breast cancer patients who are at high risk of disease recurrence.

Abemaciclib is an oral drug which stops the production of proteins in the body called CDK4 and CDK6, which are responsible for promoting cell growth. This mechanism and abemaciclib has been shown to have antitumour activity and significantly reduce tumour growth, including breast cancer.

This clinical trial is an industry sponsored (Eli Lilly) trial.

Enrolment: Closed