A Phase III Study of Enzalutamide Alone or with Abiraterone and Prednisone for Metastatic Castration-Resistant Prostate Cancer

Full Title

Phase III Trial Of Enzalutamide (NSC # 766085) Versus Enzalutamide, Abiraterone And Prednisone For Castration Resistant Metastatic Prostate Cancer (Alliance #A031201)


Prostate cancers initially need the male hormone testosterone for growth. Hormone therapies that lower the level of testosterone are among the most effective treatments for prostate cancers that have spread to other organs (metastasized). The benefits of hormone treatments do not last, however. Over time, many prostate cancers continue to grow despite hormonal therapies (and are called “castration-resistant” prostate cancer, or CRPC).

Enzalutamide and abiraterone acetate are drugs used to treat CRPC. They work in different ways to block the hormones that prostate cancer needs to grow. Enzalutamide is approved for treating men with metastatic CRPC who have already received chemotherapy; in this study, it will be assessed in men who have not yet had chemotherapy for metastatic CRPC. Abiraterone, which is given with prednisone, is approved for treating men with metastatic CRPC when given before or after chemotherapy. However, the three drugs have never been evaluated together.

In this study, patients with metastatic CRPC will be randomly assigned to receive one of two treatment regimens: enzalutamide alone, or enzalutamide with abiraterone and prednisone. Researchers will see how the two groups fare to determine if one regimen in more effective than the other. All three drugs are taken orally (by mouth).


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

  • Patients must have metastatic castration-resistant prostate cancer.
  • Patients may not have had prior treatment with taxane-based chemotherapy (such as docetaxel) for metastatic disease. If a patient did previously receive a taxane drug for local disease or when his PSA level was rising, no more than 6 cycles may have been given, and at least 6 months must have passed between completion of chemotherapy and entry into the study.
  • At least 4 weeks must have passed since completion of other therapies other than testosterone-lowering agents and entry into the study.
  • Patients must be physically well enough that they are fully ambulatory, capable of all self care, and are capable of all but physically strenuous activities. As an example, patients must be well enough that they would be able to carry out office work or light housework.
  • This study is open to patients age 18 and older.

For more information about this study and to inquire about eligibility, please contact Dr. Michael Morris at 646-422-4469.