This clinical trial studies whether measuring circulating tumor deoxyribonucleic acid (ctDNA) tumor fraction (TF) can be used to help guide the early stopping (discontinuation) of lutetium Lu 177 vipivotide tetraxetan (177Lu-PSMA-617) in patients with castration-resistant prostate cancer that has spread from where it first started (primary site) to other places in the body (metastatic). Many types of tumors tend to lose cells or release different types of cellular products including their deoxyribonucleic acid, which is referred to as ctDNA, into the bloodstream before changes can be seen on scans. Health care providers can measure the level of ctDNA in blood or other bodily fluids to determine which patients are at higher risk for the disease to grow, spread, or get worse or come back after a period of improvement. ctDNA TF is a type of ctDNA measurement. Research has shown ctDNA TF may be a promising way to predict which patients will respond to 177Lu-PSMA-617 treatment. Measuring ctDNA TF may help doctors identify which patients may benefit from changing treatments sooner, which may be an effective way to guide early 177Lu-PSMA-617 treatment discontinuation in patients with metastatic castration-resistant prostate cancer.
Willing and able to provide informed consent
Adult males ≥ 18 years age
History of histologically confirmed adenocarcinoma of the prostate without evidence of neuroendocrine or small cell differentiation. If histology is not available, patients must have metastatic disease typical of prostate cancer (i.e., involving bone or pelvic lymph nodes or para-aortic lymph nodes)
Evidence of metastatic disease on bone scan or CT scan
Evidence of serious and/or unstable pre-existing medical, psychiatric or other condition that could interfere with patient safety or provision of informed consent to participate in this study
Evidence of metastatic neuroendocrine/small cell prostate cancer (NEPC). Note: baseline biopsy is not required
Patients receiving any systemic therapy (aside from a luteinizing hormone-releasing hormone [LHRH] analogue) or radiotherapy within 2 weeks prior to study treatment
Persistent toxicities (CTCAE grade > 2) from prior cancer therapy, excluding alopecia and stable neuropathy
University of Washington
Lead sponsor
Institute for Prostate Cancer Research (IPCR)
Collaborator