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

Inclusion Criteria:

- Histologically or cytologically confirmed adenocarcinoma of the prostate at initial
biopsy, without neuroendocrine differentiation, signet cell, or small cell features;

- Prostate cancer initially treated by radical prostatectomy or radiotherapy (including
brachytherapy) or both, with curative intent;

- PSA doubling time ≤ 9 months;

- 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;

- Serum testosterone ≥ 150 ng/dL (5.2 nmol/L).

Exclusion Criteria:

- Prior or present evidence of distant metastatic disease as assessed by radiographic
imaging;

- 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.;

- Prior cytotoxic chemotherapy, aminoglutethimide, ketoconazole, abiraterone acetate, or
enzalutamide for prostate cancer;

- Prior systemic biologic therapy, including immunotherapy, for prostate cancer;

- Major surgery within 4 weeks before randomization;

- Treatment with 5-α reductase inhibitors (finasteride, dutasteride) within 4 weeks of
randomization;

- Known or suspected brain metastasis or active leptomeningeal disease;

- History of another invasive cancer within 3 years before screening, with the exception
of fully treated cancers with a remote probability of recurrence