Dr. Brufsky on the Efficacy of Enobosarm in ER+/AR+ Breast Cancer

Adam M. Brufsky, MD, PhD, FACP, professor of medicine, University of Pittsburgh School of Medicine (UPMC), associate chief, Division of Hematology/Oncology, Department of Medicine, medical director, Magee-Women’s Cancer Program of UPMC Hillman Cancer Center, associate director of Clinical Investigations, UPMC Hillman Cancer Center, codirector, Comprehensive Breast Cancer Center, discusses efficacy data with enobosarm in metastatic estrogen receptor (ER)–positive, androgen receptor (AR)–positive, HER2-negative breast cancer.

Several clinical trials explored the utility of enobosarm as a treatment for patients with breast cancers, including AR-positive triple-negative breast cancer, says Brufsky. ​Findings from a phase 2 clinical trial (NCT02463032) evaluated enobosarm in patients with progressive ER-positive, AR-positive metastatic breast cancer and demonstrated a reasonable response rate with the agent, Brufsky says. 

It was discovered that if a patient had greater than 40% staining of the AR, the response rate with enobosarm was about was 34% with a clinical benefit rate (CBR) of about 52%, Brufsky continues. Moreover, the median progression-free survival (PFS) was over 5.5 months and was improved compared with the median PFS in patients with under 40% staining of the AR, Brufsky explains. The CBR with those patients was 14%, with almost no responses observed, Brufsky concludes.