CORT125281 is a selective glucocorticoid receptor (GR) antagonist. In this study, CORT125281 will be administered orally in combination with enzalutamide to patients with metastatic castration-resistant prostate cancer (mCRPC) to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of the regimen. The study consists of two phases: a dose-determination phase and an expansion phase. The dose determination phase is designed to determine dose-limiting toxicities and the RD of CORT125281 plus enzalutamide in patients with mCRPC. Once the recommended dosing regimen has been determined, the following expansion cohorts will be enrolled and treated with CORT125281 plus enzalutamide at the recommended dose level.~Abi-Resistant Cohort: Patients who have progressed during treatment with abiraterone, and have received no other androgen receptor (AR)-blocking therapies~ARant-Resistant Cohort: Patients who have progressed during treatment with enzalutamide or other second-generation AR inhibitors.~The effect of food on CORT125281 PK will be assessed in a portion of the patients enrolled in the Expansion Phase. The two expansion cohorts will be enrolled in parallel.~In each phase of the study, routine assessments of safety and tolerability will be performed and samples will be collected to determine standard PK parameters for CORT125281, enzalutamide, and their major metabolites. PD, quality of life evaluations and preliminary evaluations of anti-tumor activity of CORT125281 with enzalutamide will be performed throughout the study.
This is an open-label, Phase 1/2a dose escalation study with an expansion phase to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD), and preliminary efficacy of CORT125281 in combination with enzalutamide in patients with metastatic castration-resistant prostate cancer (mCRPC) to identify a recommended dose (RD) for Phase 2 studies.