Safety and Efficacy Study of Enzalutamide Plus Leuprolide in Patients With Nonmetastatic Prostate Cancer (EMBARK)

Inclusion Criteria:

1. Histologically or cytologically confirmed adenocarcinoma of the prostate at initial biopsy, without neuroendocrine differentiation, signet cell, or small cell features;
2. Prostate cancer initially treated by radical prostatectomy or radiotherapy (including brachytherapy) or both, with curative intent;
3. PSA doubling time ≤ 9 months;
4. Screening PSA by the central laboratory ≥ 1 ng/mL for patients who had radical prostatectomy (with or without radiotherapy) as primary treatment for prostate cancer and at least 2 ng/mL above the nadir for patients who had radiotherapy only as primary treatment for prostate cancer;
5. Serum testosterone ≥ 150 ng/dL (5.2 nmol/L).

Exclusion Criteria:

1. Prior or present evidence of distant metastatic disease as assessed by radiographic imaging;
2. Prior hormonal therapy. Neoadjuvant/adjuvant therapy to treat prostate cancer ≤ 36 months in duration and ≥ 9 months before randomization, or a single dose or a short course (≤ 6 months) of hormonal therapy given for rising PSA ≥ 9 months before randomization is allowed.;
3. Prior cytotoxic chemotherapy, aminoglutethimide, ketoconazole, abiraterone acetate, or enzalutamide for prostate cancer;
4. Prior systemic biologic therapy, including immunotherapy, for prostate cancer;
5. Major surgery within 4 weeks before randomization;
6. Treatment with 5-α reductase inhibitors (finasteride, dutasteride) within 4 weeks of randomization;
7. Known or suspected brain metastasis or active leptomeningeal disease;
8. History of another invasive cancer within 3 years before screening, with the exception of fully treated cancers with a remote probability of recurrence