This is a Phase 1/2, open-label, multi-center, non-randomized, dose-escalation study to be conducted in two parts: the Dose Escalation Phase and the Dose Expansion Phase. The Dose Escalation Phase will determine the Maximum Tolerated Dose (MTD) and recommended Phase 2 dose(s) (RP2D) of PT-112 Injection and evaluate its safety and tolerability, and PK (pharmacokinetics).

The Dose Escalation Phase is complete and no longer enrolling.

The Dose Expansion Phase has two cohorts: one cohort for the study of PT-112 in patients with thymoma and thymic carcinoma (Cohort A), and one cohort for the study of PT-112 in metastatic castrate-resistant prostate cancer (mCRPC) (Cohort D).

This is a Phase 1/2, open-label, multi-center, non-randomized, dose-escalation study to be conducted in two parts: the Dose Escalation Phase, and the Dose Expansion Phase

The Dose Escalation Phase and the Dose Expansion Thymoma Cohort are complete and no longer enrolling.

The Dose Expansion Phase of the study of PT-112 in metastatic castrate-resistant prostate cancer (mCRPC) is open and enrolling.

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.