Study of ORIC-944 in Patients With Metastatic Prostate Cancer

Inclusion Criteria: * Patients with metastatic prostate cancer * Must have undergone bilateral orchiectomy or be willing to continue GnRH analogue or antagonist to maintain castrate levels of testosterone * Prior therapies: Part I (single agent ORIC-944 dose escalation): Any number of prior therapies are allowed, but must have progressed after at least one line of next generation ARPI (abiraterone, apalutamide, darolutamide, or enzalutamide) and must not have received more than 2 chemotherapy regimens in the mCRPC setting Part II (ARPI combination dose escalation): Must have received only 1 prior line of ARPI (abiraterone, apalutamide, darolutamide, or enzalutamide) in any setting; may have also received up to 1 prior line of chemotherapy in the mCSPC setting Part III (ARPI combination dose optimization): In addition to up to 1 prior line of chemotherapy in the mCSPC setting: * Cohorts A and B: received only one 1 prior line of abiraterone in any setting * Cohorts C and D: received only one 1 prior line of apalutamide, darolutamide, or enzalutamide in any setting: * Evidence of progressive disease by PCWG3 criteria for study entry * rising PSA, defined as a minimum of 2 rising values obtained a minimum of one week apart with the latest result being at least 2.0 ng/mL (or 1.0 ng/mL if PSA rise is the only indication of progression), or * confirmation of 2 new bone lesions on last systemic therapy, or * soft tissue progression per RECIST 1.1 * Measurable …