Safety, Tolerability, and Efficacy of CP-PCA07 in Combination With Enzalutamide in Patients With Castration-Resistant Prostate Cancer

The purpose of this clinical study is to evaluate the safety, tolerability, and efficacy of CP-PCA07 in combination with enzalutamide in patients with castration-resistant prostate cancer (CRPC). This is an open-label, dose-escalation, multicenter Phase 1 study. The primary objective is to assess the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) to determine the recommended Phase 2 dose (RP2D) of the combination therapy. The secondary objective is to assess changes in Prostate-Specific Antigen (PSA) levels and pharmacokinetic characteristics. Exploratory objectives include assessment of tumor response, disease control, progression-free survival, and biomarker analyses, including AR-V7 status, according to RECIST version 1.1 and other applicable criteria.

Inclusion Criteria: * 1\. Male patients aged ≥19 years at the time of providing written informed consent. * 2\. Patients with histologically or cytologically confirmed castration-resistant prostate cancer without small-cell features, who have experienced treatment failure with monotherapy of Enzalutamide or Abiraterone. * 3\. Patients with a serum testosterone level \< 50 ng/dL at screening. * 4\. Patients with an increase in PSA compared to baseline, confirmed by two consecutive measurements within 8 weeks prior to the date of written informed consent (with at least 1 week between measurements and an increase of ≥ 50% compared to baseline). * 5\. Patients with PSA levels ≥ 2 ng/mL both prior to the date of written informed consent and at screening. * 6\. Patients with an ECOG performance status ≤ 2 and an expected survival of at least 6 months. * 7\. Patients whose spouse or partner is a woman of childbearing potential must agree to use one of the protocol-specified highly effective methods of contraception from the time of study participation consent until 3 months after the last administration of the investigational product. * 8\. Patients who voluntarily agree to participate in this study and provide written informed consent. Exclusion Criteria: * 1\. Patients who have received chemotherapy, chemoradiotherapy, biologic therapy, immunotherapy, or radiotherapy within 4 weeks prior to the first administration of the investigational product (for docetaxel or cabazitaxel therapy, within 9 weeks prior to the screening date). * 2\. Patients diagnosed with immunodeficiency or who are in an immune-suppressed condition. * 3\. Patients with autoimmune diseases. * 4\. Patients with a pacemaker or severe heart failure \[Class III or IV heart failure according to the New York Heart Association (NYHA) classification\], or patients with uncontrolled arrhythmia (all patients with implanted medical devices other than a pacemaker are excluded). * 5\. Patients with a history of chronic liver disease or evidence of cirrhosis. * 6\. Patients with a history of gastrectomy or other conditions that may affect drug absorption. * 7\. Patients with a history of deep vein thrombosis, pulmonary embolism, acute coronary syndrome, or major cerebrovascular disease within 6 months prior to screening. * 8\. Patients with a history of major surgery requiring general anesthesia or assisted ventilation within 4 weeks prior to screening. * 9\. Patients with active hepatitis B, a history of hepatitis B, or known active hepatitis C virus infection at screening. * 10\. Patients who meet any of the following laboratory criteria at screening: * ① Absolute neutrophil count (ANC) \< 1,500/uL without G-CSF administration within 2 weeks prior to screening * ② Platelet \< 100,000/uL without transfusion within 2 weeks prior to screening * ③ Hemoglobin \< 9.0 g/dL without transfusion within 2 weeks prior to screening * ④ Serum creatinine \> 1.8 mg/dL or eGFR (or GFR) \< 40 mL/min/1.73 m2 * ⑤ AST and ALT \> 2.5 x ULN * ⑥ Total bilirubin \> 2.0 x ULN * 11\. Patients expected to have hypersensitivity to the active ingredient or components of the investigational product. * 12\. Patients who have received another investigational drug or investigational medical device within 4 weeks prior to the first administration of the investigational product. * 13\. Patients deemed by the investigator to be unsuitable for participation in the study or unable to comply with the study requirements due to other diseases or conditions.