To Evaluate the Safety, Tolerability, Radiation Dosimetry, Pharmacokinetics, and Preliminary Antitumor Efficacy of SRT-017 in Patients With PSMA-Positive Metastatic Castration-Resistant Prostate Cancer (mCRPC)
This is a single-arm, open-label study to evaluate the safety, tolerability and preliminary anti-tumor efficacy of SRT-017 radioligand therapy in patients with PSMA-Positive Metastatic Castration-Resistant Prostate Cancer (mCRPC). All eligible participants will receive SRT-017 intravenous treatment. The primary objectives are to assess safety and tolerability. Secondary objectives include radiation dosimetry, pharmacokinetics, and preliminary antitumor activity.
• Male participants aged 18 years or older.
• Histologically or cytologically confirmed prostate adenocarcinoma with metastatic castration-resistant prostate cancer (mCRPC). mCRPC is defined as disease progression under continuous androgen-deprivation therapy (ADT) or after prior bilateral orchiectomy, with serum testosterone maintained at castrate level (\<50 ng/dL or \<1.7 nmol/L), meeting at least one of the Prostate Cancer Working Group 3 (PCWG3) progression criteria: PSA progression (PSA ≥1 ng/mL, ≥25 % increase compared with PSA nadir with an absolute rise ≥2 ng/mL confirmed by two consecutive measurements at least 1 week apart); or radiographic progression (≥2 new bone metastatic lesions on bone scan, or soft-tissue disease progression per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1)).
• Disease progression after treatment with at least one novel androgen-axis drug (NAAD), including abiraterone, enzalutamide, apalutamide, or darolutamide.
• Prior chemotherapy, or participants who are ineligible for chemotherapy or decline chemotherapy.
• PSMA-positive lesions confirmed by PSMA-PET/CT imaging; PSMA-positive is defined as tumor lesion uptake higher than liver background uptake.
• At least one measurable lesion by RECIST 1.1 criteria OR at least one bone metastasis lesion by PCWG3 criteria.
• Eastern Cooperative Oncology Group (ECOG) performance status score ≤ 1.
• Estimated life expectancy of at least 6 months.
• No transfusion of blood products, hematopoietic growth factors, or albumin within 14 days before baseline laboratory tests, and adequate organ function as follows: hematologic: absolute neutrophil count ≥ 1.5 × 10⁹/L, white blood cell count ≥ 3.0 × 10⁹/L, platelet count ≥ 100 × 10⁹/L, hemoglobin ≥ 9 g/dL; hepatic: albumin ≥ 30 g/L, total bilirubin ≤ 1.5 × upper limit of normal (ULN), alanine aminotransferase (ALT) / aspartate aminotransferase (AST) ≤ 3 × ULN (without liver metastases) or ALT/AST ≤ 5 × ULN (with liver metastases); renal: serum creatinine ≤ 1.5 × ULN; coagulation: international normalized ratio (INR) ≤ 1.5, activated partial thromboplastin time (APTT) ≤ 2 × ULN.
• Willing to comply with radiation-protection instructions and scheduled study follow-up procedures.
• Able to understand study procedures and voluntarily provide written informed consent, and willing to comply with all study-related assessments and follow-up requirements.