Two TraCer PositROn EmiSSion Tomography ComBination for Efficacy EstimatiOn of Prostate Specific Membrane Antigen Radioligand Therapy in Patients With Metastatic Prostate Cancer


Single-arm, open-label, phase II trial in 200 competent adult male patients with Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-3 and progressive metastatic prostate cancer, failing, failed, refused, not eligible for or no access to further approved lines of therapy. Patients will undergo sequential FDG positron emission tomography (PET) and 18F-DCFPyL PET to assess FDG/DCFPyL concordance fraction. Patients with DCFPyL/FDG concordance of 50% or greater will be treated with 131I-PSMA-1095 radioligand therapy (RLT). Best post-treatment serum prostate specific antigen response will be compared to concordance fraction.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Treatment
    • Masking: None (Open Label)
  • Study Primary Completion Date: January 15, 2024


  • Drug: 131I-PSMA-1095 Radioligand Therapy (RLT)
    • Intravenous injection of 100 mCi of 131I-PSMA-1095, Q8 weeks up to a maximum of 4 doses.

Arms, Groups and Cohorts

  • Experimental: 131I-PSMA-1095 Radioligand Therapy (RLT)
    • Intravenous injection of 100 mCi of 131I-PSMA-1095 RLT, Q8 weeks up to a maximum of 4 doses

Clinical Trial Outcome Measures

Primary Measures

  • Serum prostate specific antigen (PSA)
    • Time Frame: 3 months post last dose of RLT
    • The best serum prostate specific antigen (PSA) response will be calculated for each patient as: pre-treatment PSA minus lowest post-treatment PSA divided by pre-treatment PSA. Best PSA response will be reported as percent reduction (or increase) from baseline.

Secondary Measures

  • AE
    • Time Frame: 3 months post last dose of RLT
    • Adverse events as per CTCAE v5.0

Participating in This Clinical Trial

Inclusion Criteria

  • Male – Age 18 years or older – Documented metastatic adenocarcinoma of the prostate – Under active medical oncology care – ECOG performance status 0 – 3, inclusive – Able to understand and provide written informed consent – Able to tolerate the physical requirements of two PET/CT scans including lying for up to 30 minutes – Progressive disease on any of: bone scan, CT, MRI or serum PSA as judged by the investigator – Serum prostate specific antigen ≥ 1 ng/ml at baseline or CT/MRI soft-tissue measurable disease as per RECIST v1.1 – Failed, failing, refused, no access to or not eligible for any approved prostate cancer therapies including but not limited to: ADT, NAAD (e.g., abiraterone, enzalutamide, darolutamide or apalutamide), docetaxel, cabazitaxel, radium-223 and oligometastatic RTX – Life expectancy of at least 3 months as judged by the investigator Exclusion Criteria:

  • Medically unstable (e.g. acute cardiac or respiratory distress or hypotensive) – Exceeding the weight limit of the PET/CT bed (approximately 400 lbs.) or who cannot fit through the PET/CT bore (approximately 70 cm diameter) – Unmanageable claustrophobia – Prior failure of PSMA RLT – Prior hemi-body irradiation – Impaired organ function as evidenced by any of the following laboratory values: – Absolute neutrophil count < 1.5 x109/L – Platelet count < 75 x109/L – Hemoglobin < 85 g/L – Albumin < 2.5 g/dL (25 g/L) – Total bilirubin > 2 x ULN (unless in instances of Gilbert's disease) – AST or ALT > 2.5 x ULN (or > 5.0 x ULN in the presence of liver metastases)

Gender Eligibility: Male

Male only.

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Sir Mortimer B. Davis – Jewish General Hospital
  • Provider of Information About this Clinical Study
    • Principal Investigator: Stephan Probst, MD, Chief of Nuclear Medicine – Sir Mortimer B. Davis – Jewish General Hospital
  • Overall Official(s)
    • Stephan Probst, MD, Principal Investigator, Jewish General Hospital

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