Approximately 26 to 49 patients will be entered into this trial, approximately 12 to 24 patients in the phase I safety run in cohort depending on number of patients required to determine RP2D and schedule and between 14 and 25 patients in the phase II reversal of enzalutamide resistance cohort (the investigators predict around 50% of these patients will enter the phase II enzalutamide resistance run in cohort first).