Study of HLD-0915 in Patients With Metastatic Prostate Cancer

Patients must meet the following criteria to be eligible study participation: Key Inclusion Criteria: All Study Arms (Phase 1 Part 1 \& 2, Phase 2 Part 1, Part 2A, 2B, 2C \& 2D): Males ≥ 18 years old Histological, pathological, and/or cytological confirmation of prostate adenocarcinoma Adequate hematological, renal, and hepatic function. Able to swallow oral medication mCRPC Arms: (Phase 1 Part 1 \& 2, Phase 2 Part 1): Prior orchiectomy or ongoing androgen-deprivation therapy and a castrate level of serum testosterone Progressive mCRPC defined as having demonstrated PSA progression on the prior regimen SOAR Arm (Phase 2 Part 2A) mHSPC with distant metastatic disease based on conventional imaging PSA ≥0.2 ng/mL, following treatment with next generation ARPI for at least 180 days and up to 365 days No evidence of radiographic or PSA progression while receiving ARPI mHSPC arms (Phase 2 Part 2B, 2C \& 2D) serum testosterone \>150ng/ml mHSPC with distant metastatic disease based on conventional imaging and PSA \>2.0 ng/mL Key Exclusion Criteria: All arms (Phase 1 Part 1 \& 2, Phase 2 Part 1, Part 2A, 2B, 2C \& 2D): Has experienced a recent major bleed or has a known bleeding disorder Tumors exhibiting neuroendocrine or small cell carcinoma component by histopathology Receiving continuous corticosteroids at prednisone-equivalent dose of \>10 mg/day Prior or ongoing significant medical condition mCRPC arms: (Phase 1 Part 1 \& 2, Phase 2 Part 1): Has received systemic anti-cancer therapy or investigational drugs within 2 weeks prior to first dose of study drug with certain exceptions requiring longer washout periods SOAR arm (Phase 2 Part 2A) Has received any prior cytotoxic chemotherapy for prostate cancer mHSPC arms (Phase 2 Part 2B, 2C \& 2D) regional pelvic lymph node disease only