A Phase II Study of Presurgical Fulvestrant with or without Enzalutamide in Estrogen Receptor-Positive/HER2-Negative Breast Cancer


Full Title

Randomized Phase II Trial of Preoperative Fulvestrant with or without Enzalutamide in ER+/Her2- Breast Cancer


Treatments given to weaken and destroy breast cancer before surgery are called “neoadjuvant” treatments. Neoadjuvant or presurgical therapy is frequently used; its goal is to shrink breast cancer prior to surgery so that surgery is more feasible, as well as diminish the risk of a recurrence. Neoadjuvant hormonal therapy for patients with estrogen receptor-positive/HER2-negative breast cancer is effective, and has fewer side effects than chemotherapy.

The goal of this study is to evaluate two kinds of neoadjuvant hormonal therapy: fulvestrant alone or given in combination with enzalutamide. Fulvestrant is a drug used to treat breast cancer that contains estrogen receptors. It works by blocking estrogen receptors on cancer cells. Enzalutamide works by blocking a different hormone receptor called the androgen receptor. Giving enzalutamide with fulvestrant could shrink breast cancer or prevent it from returning. The purpose of this study is to determine if giving these two drugs together before breast cancer surgery is more effective than fulvestrant alone.

Fulvestrant is given as an injection. Enzalutamide is used to treat prostate cancer; its use in this study is considered investigational. It is taken orally (by mouth). Patients will be randomly assigned to receive fulvestrant alone or fulvestrant plus enzalutamide before surgery.


To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have estrogen receptor-positive, HER2-negative breast cancer that is stage 2 or greater and will be surgically removed.
  • Patients must be able to walk and do routine activities for more than half of their normal waking hours.
  • This study is for women age 18 and older.

For more information and to inquire about eligibility for this study, please contact Dr. Monica Fornier at 646-888-5240.