A Study Evaluating the Safety, Pharmacokinetics, and Clinical Effects of Intravenously Administered PT-112 Injection in Subjects With Advanced Solid Tumors and Subsequent Dose Expansion Cohorts

Key Inclusion Criteria:

* Male \>/= 18 years of age
* Histologically or cytologically confirmed adenocarcinoma of the prostate.
* Document current evidence of metastatic castration-resistant prostate cancer (mCRPC), where metastatic status is defined as having documented metastatic lesion(s) on either bone scan or CT/MRI scan.
* Patients who have received at least three prior intended life-prolonging therapies for metastatic disease.
* Eastern Collaborative Oncology Group (ECOG) Performance Status of 0-1.
* Progressive disease, either measurable on physical examination or imaging by Response Evaluation Criteria in Solid Tumors (RECIST v1.1) or PCWG3 or by informative tumor marker(s).
* Adequate organ function based on laboratory values.
* If there is a known history of brain metastases, either treated or untreated, the disease must be stable.

Key Exclusion Criteria:

* Any cytotoxic chemotherapy within 21 days prior to initiation of study drug.
* Any immunomodulatory drug therapy, anti-neoplastic hormonal therapy, immunosuppressive therapy, corticosteroids, or growth factor treatment within 14 days prior to initiation of study drug.
* Bone marrow reserve which is not adequate for participation in this trial.
* Radiotherapy within 14 days prior to baseline.
* Fraction of radiotherapy to \>25 % of active bone marrow.
* Major surgery within 28 days prior to initiation of study drug.