Targeting the Androgen Receptor in Triple-Negative Breast Cancer

Chemotherapy is the currently the only standard therapy for triple-negative breast cancer (TNBC). However, molecular assays of TNBC have identified distinct subsets of TNBC that may inform therapeutic strategies. One such subset expresses the androgen receptor (AR), and recent trials have shown that patients with AR-positive TNBC had modest response to the AR inhibitors abiraterone acetate (Ann Oncol 2016; 27:812) and bicalutamide (Clin Cancer Res 2013; 19:5505).

Now, investigators have conducted an industry-sponsored, phase II trial involving patients with AR-positive, metastatic TNBC to evaluate enzalutamide, an AR inhibitor approved for patients with metastatic prostate cancer. A total of 78 evaluable patients received oral enzalutamide u…