Dose Escalation Phase: Eligible patients will enter the study and start receiving daily doses of PCUR-101 during Cycle 1. Subsequent dose cohorts will receive the next higher dose of PCUR-101 according to a 3 + 3 design until the MTD is determined. Patients may remain on these treatment cycles if they do not progress or experience any dose limiting toxicities (DLTs).
Dose Expansion Phase: Once the MTD has been determined, approximately 18 patients in 3 cohorts will be enrolled for further evaluations of safety, PK, and preliminary clinical activity during successive 28-day cycles in the dose expansion phase: Expansion Cohort 1 will receive PCUR-101 at the MTD, Expansion Cohort 2 will receive PCUR-101 at one dose level lower than the MTD and dutasteride once daily, and Expansion Cohort 3 (6 patients) will receive PCUR-101 at one dose level lower than the MTD in patients about to start abiraterone (1000 mg QD) and prednisone (5 mg twice daily \[BID\]) as their standard of care.
