HC-1119 Versus Enzalutamide in Metastatic Castration-Resistant Prostate Cancer (mCRPC)

This study is a multinational Phase 3, randomized, double-blind, non-inferiority, efficacy and safety study of oral HC-1119 (80 mg/day) versus enzalutamide (160 mg/day) in asymptomatic or mildly symptomatic patients with progressive metastatic castration-resistant prostate cancer (mCRPC). Patients must not have been previously treated with next generation AR-Inhibitors or Androgen-biosynthesis Inhibitors, or prior progression on ketoconazole. The following assessments of prostate cancer status will be collected during the course of the trial: soft tissue disease on computed tomography (CT) scan or on magnetic resonance imaging (MRI), bone disease on radionuclide bone scans, FACT-P and EQ-5D, Brief Fatigue Inventory, and PSA. Radiographic disease progression is defined by the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1) for soft tissue disease, or the appearance of two or more new bone lesions on bone scan. Throughout the study, safety and tolerability will be assessed by the recording of adverse events, monitoring of vital signs and physical examinations, safety laboratory evaluations, and 12-lead electrocardiograms (ECGs). Blood samples for population pharmacokinetics for HC-1119 and enzalutamide and related metabolites will be collected pre-dose on Day 1 and prior to dosing on Days 8 (Week 2), 15 (Week 3) and 22 (Week 4), 29 (Week 5), 57 (Week 9), 85 (Week 13) and Day 169 (Week 25). Blood samples for calculating a 24 hour pharmacokinetic profile of HC-1119 and enzalutamide and related metabolites will be collected in a subset of 24 Caucasian (non-Chinese) patients on Day 1 and at steady state in week 9. Patients will have a safety follow-up visit 30 days after their last dose of study drug or prior to initiation of any new therapy, or an investigational agent, whichever occurs first.