Study of HLD-0915 in Patients With Metastatic Prostate Cancer

Assessment of the safety and efficacy of HLD-0915 in patients with metastatic prostate cancer who have progressed on prior systemic therapies, with further evaluation in additional prostate cancer populations.

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