This is a single-center, open-label, study of Prostate-Specific Membrane Antigen (PSMA)-targeted radionuclide therapy with 177Lu-PSMA-617 in combination with pembrolizumab in participants with metastatic castrate-resistant prostate cancer (mCRPC) who have previously progressed on at least one prior androgen pathway inhibitor (e.g., abiraterone, enzalutamide, apalutamide).
Histologically confirmed prostate adenocarcinoma that is progressive metastatic castration-resistant prostate cancer by Prostate Cancer Clinical Trials Working Group 3 (PCWG3) criteria at the time of study entry.
Male participants who are at least 18 years of age on the day of signing informed consent.
Castrate level of serum testosterone at study entry (< 50 ng/dL). Note: Participants without prior bilateral orchiectomy are required to remain on Luteinizing hormone-releasing hormone (LHRH) analogue treatment for duration of study.
Prior progression on at least one second generation androgen signaling inhibitor including abiraterone, apalutamide, darolutamide, and/or enzalutamide.
De novo small cell neuroendocrine prostate cancer will not be allowed due to putative lower PSMA expression in this tumor subtype. Note-Treatment-emergent small cell neuroendocrine prostate cancer detected in metastatic tumor biopsy is not excluded.
Soft tissue lesions (lymph nodes > 1.5 centimeter (cm) in short axis, visceral/soft tissue lesions > 1 cm) on screening Computerized tomography (CT) that are negative on PSMA PET. Note: Negative lesions on PSMA PET are defined as those with uptake below the background liver.
Has received other systemic anti-cancer therapies administered within 14 days, or 5 half-lives, whichever is shorter, prior to initiation of study treatment. Note: LHRH analogues are the exception.
Untreated brain metastases at study entry.
University of California, San Francisco
Lead sponsor
Merck Sharp & Dohme LLC
Collaborator
Prostate Cancer Foundation
Collaborator