Relative Bioavailability Study of Enzalutamide in Prostate Cancer Patients

A Phase I, Open-label, Randomized, Parallel, Relative Bioavailability Study Comparing a Capsule and a Tablet Formulation of Enzalutamide Following Multiple Once Daily Doses of 160 mg Enzalutamide in Male Subjects With Prostate Cancer

A multiple dose relative bioavailability study in patients with prostate cancer comparing a capsule and a tablet formulation of enzalutamide.

Inclusion Criteria:

• Histologically confirmed prostate cancer (all stages) for whom androgen deprivation therapy is indicated (except when indicated in a neoadjuvant/adjuvant setting). Subjects may be on ongoing androgen deprivation therapy with a gonadotropin releasing hormone (GnRH) analogue or orchiectomy (i.e., medical or surgical castration) at study entry.

• Progressive disease by Prostate-specific antigen (PSA) or imaging. Disease progression for study entry is defined as one or more of the following 3 criteria:

  • PSA progression defined by a minimum of 2 rising PSA levels with an interval of ≥1 week between each determination. The PSA value during the pre-investigational period should be ≥2 μg/L (2 ng/mL);
  • Soft tissue disease progression defined by the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1) for soft tissue disease
  • Bone disease progression defined by two or more new lesions on bone scan

Exclusion Criteria:

• Treatment with chemotherapy within 4 weeks prior to enrollment (Day 1 visit) or plans to initiate treatment with chemotherapy during the study.
• History of seizure or any condition that may predispose to seizure. Also, history of loss of consciousness, or transient ischemic attack within 12 months prior to enrollment (Day 1 visit).
• Patients who previously received treatment with Enzalutamide.
• Concomitant use of drugs that are potent inducers and/or inhibitors of CYP3A4 and CYP2C8.
• Confirmed CYP2C8 poor metabolizer status based on genotyping analysis.