Metastatic Castration Resistant Prostate Adenocarcinoma

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.

This phase I trial compares the effect of lutetium Lu 177 (177\^Lu)-prostate-specific membrane antigen (PSMA)-617 in combination with Sipuleucel-T to 177\^Lu-PSMA-617 alone in treating patients with prostate that has spread from where it first started (primary site) to other places in the body (metastatic) and has continued to grow and spread despite surgical or medical intervention to block androgen production (castration-resistant). 177\^Lu-PSMA-617, a type of radioconjugate, binds to a protein called PSMA, which is found on some prostate tumor cells. It gives off radiation that may kill the tumor cells. Sipuleucel-T, a type of vaccine and a type of cellular adoptive immunotherapy, is made from immune system cells. The cells are treated with a protein that is made by combining a protein found on prostate tumor cells with a growth factor. When the cells are injected back into the patient, they may stimulate T cells to kill prostate tumor cells. Giving 177\^Lu-PSMA-617 in combination with sipuleucel-T may be safe, tolerable, and/or effective compared to 177\^Lu-PSMA-617 alone in treating patients with metastatic castration-resistant prostate cancer.