Treatment of Metastatic Castration-Resistant Prostate Cancer With Homologous Recombination Deficiency

Key Inclusion Criteria:

* Men (≥ 18 years of age) with histologically or cytologically confirmed adenocarcinoma or poorly differentiated adenocarcinoma of the prostate without neuroendocrine differentiation with HRD deficiency by CTC-HRD assay and/or deleterious germline or somatic mutation in BRCA1 or BRCA2; mCRPC measurable disease and/or bone disease. • PSA progression with ≥ 3 rising PSA levels with ≥ 1 week between determinations and a screening PSA ≥ 2 μg/L (2 ng/mL).
* Must be surgically or medically castrated with serum testosterone levels of ≤1.73 nmol/L (50 ng/dL), must have received ≥ 1 prior androgen receptor-targeted therapy, and must have received ≥ 1 taxane-based therapy.
* mCRPC with 1 or 2 of the following:
* Measurable disease per RECIST v1.1
* Bone disease
* CTC-HRD+ or BRCA1/2 mutation
* PSA progression (PCWG3 criteria)
* ≥1 androgen receptor-targeted therapy (eg, abiraterone acetate/prednisone or enzalutamide) for mCRPC with progressive disease
* ≥1 taxane for metastatic prostate cancer

Key Exclusion Criteria:

* Chemotherapy, hormonal therapy, biologic therapy, radionuclide therapy, immunotherapy, investigational agent, anticancer Chinese medicine, or herbal remedies ≤ 5 half-lives if the half-life is known, ≤ 14 days if not known, before start of study treatment
* Continued treatment with a bisphosphonate or denosumab is allowed, if administered at a stable dose \> 28 days before start of study treatment
* Radiotherapy ≤ 21 days (≤ 14 days, if single fraction of radiotherapy) before start of study treatment

Prior treatment for prostate cancer with any of the following:

* poly ADP ribose polymerase (PARP) inhibitor
* Platinum
* Cyclophosphamide
* Mitoxantrone

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.