Given the activity of docetaxel in patients with progressive, metastatic castration-resistant prostate cancer, this study is being undertaken to evaluate the activity of tesetaxel, an orally bioavailable taxane, in chemotherapy-naive and chemotherapy-exposed patients.

Key Inclusion Criteria:

• At least 18 years of age
• Histologically confirmed prostate cancer, currently with progressive disease
• Evidence of metastatic disease
• Castrate level of testosterone (< 50 ng/dL)
• Eastern Cooperative Oncology Group performance status 0 or 1
• Chemotherapy-naïve
• Adequate bone marrow, hepatic, and renal function
• Ability to swallow an oral solid-dosage form of medication

Key Exclusion Criteria:

• History or presence of brain metastasis or leptomeningeal disease
• Operable cancer
• Uncontrolled diarrhea
• Uncontrolled nausea or vomiting
• Known malabsorptive disorder
• Currently active second malignancy other than non-melanoma skin cancers
• Human immunodeficiency virus (HIV) infection based on history of positive serology
• Significant medical disease other than cancer
• Presence of neuropathy > Grade 2 (National Cancer Institute Common Toxicity Criteria [NCI CTC]; v4.0)
• Need for other anticancer treatment
• Need to continue any regularly-taken medication that is a potent inhibitor or inducer of the CYP3A pathway or P-glycoprotein activity
• Less than 2 weeks since use of a medication or ingestion of an agent, beverage, or food that is a potent inhibitor or inducer of the CYP3A pathway or P-glycoprotein activity
• Less than 4 weeks since use of another investigational agent