Dr. O'Shaughnessy on the Rationale for the MonarchE Trial in Breast Cancer

Joyce A. O'Shaughnessy, MD, co-chair of Breast Cancer Research and chair of Breast Cancer Prevention Research at Baylor-Sammons Cancer Center of Texas Oncology, as well as the 2016 Giant of Cancer Care® in Community Outreach, discusses the rationale for the monarchE trial in breast cancer.

 Abemaciclib (Verzenio), a potent CDK4/6 inhibitor, has demonstrated a survival advantage in patients with metastatic breast cancer who were previously treated with an aromatase inhibitor (AI) and fulvestrant (Faslodex), says O’Shaughnessy. The agent appears to be particularly beneficial in patients with breast cancer who have virulent disease with poor prognoses. This could include those with short disease-free intervals, liver metastases, grade 3 disease, or progesterone receptor–negative disease, O’Shaughnessy explains.

The monarchE trial evaluated adjuvant abemaciclib in combination with endocrine therapy in patients with hormone receptor–positive, HER2-negative, node-positive, high-risk, early-stage breast cancer.

 Currently, these patients receive AIs. If patients are premenopausal, they receive AIs in combination with luteinizing hormone-releasing hormone agonists. However, patients with 4 or more nodes, 1 to 3 nodes and a tumor that is greater than 5 cm, or grade 3 disease, have unfavorable prognoses in the curative setting. As such, there was rationale to evaluate abemaciclib as a novel therapy in this space because it demonstrated efficacy in the metastatic setting, O'Shaughnessy concludes.