Phase I/II Trial of Pembrolizumab and Androgen-receptor Inhibitor With or Without 225Ac-J591 for Progressive Metastatic Castration Resistant Prostate Cancer
This is a phase I/II study investigating the combination of 225Ac-J591 (a drug that can deliver radiation to prostate cancer cells) with pembrolizumab (immunotherapy, a drug that increases the immune system's ability to destroy cancer cells). This study will assess whether 225Ac-J591 + pembrolizumab + androgen receptor inhibitor (ARI) is more effective against prostate cancer than pembrolizumab + ARI alone.
• Male participants who are at least 18 years of age on the day of signing informed consent with histologically confirmed diagnosis of prostate adenocarcinoma.
• A male participant must agree to use a contraception during the treatment period and for at least 4 months after the last dose of study treatment and refrain from donating sperm during this period.
• Documented progressive metastatic CRPC based on Prostate Cancer Working Group 3 (PCWG3) criteria, which includes at least one of the following criteria: PSA progression, Objective radiographic progression in soft tissue, New bone lesions
• Evaluable for response with at least one of the following:
‣ Measurable disease by RECIST 1.1
⁃ Detectable (\>0) CTC by CellSearch
⁃ PSA of at least 5ng/dL
• ECOG performance status of 0-1
• Have serum testosterone ≤ 50 ng/dL. Subjects must continue primary androgen deprivation with an LHRH/GnRH analogue (agonist/antagonist) if they have not undergone orchiectomy.
• Have previously been treated with at least one of the following in any disease state: Androgen receptor inhibitor (ARI, such as enzalutamide, apalutamide or darolutamide), CYP 17 inhibitor (such as abiraterone acetate). These drugs may have been initiated in the metastatic hormone sensitive (i.e. non-castrate) or non-metastatic (M0) CRPC setting provided they meet criteria for progressive mCRPC at study entry.
• Age ≥ 18 years
• Patients must have normal organ and marrow function as defined: Absolute neutrophil count \>2,000 cells/mm3, Hemoglobin ≥ 9 g/dL, Platelet count \>150 x 10\^3/mcL, Serum creatinine \<1.5 x upper limit of normal (ULN) or calculated creatinine clearance ≥ 50 mL/min/1.73 m2 by Cockcroft-Gault, Serum total bilirubin \<1.5 x ULN (unless due to Gilbert's syndrome in which case direct bilirubin must be normal), Serum AST and ALT \<3 x ULN in absence of liver metastases; \< 5x ULN if due to liver metastases (in both circumstances bilirubin must meet entry criteria), Serum internalized normalized ratio (INR) OR prothrombin time (PT) AND activated partial thromboplastin time (aPTT) must be ≤1.5 x ULN unless participant is receiving anticoagulant therapy as long as PT or aPTT is within therapeutic range of intended use of anticoagulants.
• Ability to understand and the willingness to sign a written informed consent document.