Abemaciclib Before 177Lu-PSMA-617 for the Treatment of Metastatic Castrate Resistant Prostate Cancer

This phase I/II trial tests the safety, side effects, and best dose of abemaciclib and whether it works before 177Lu-PSMA-617 in treating patients with castration resistant prostate cancer that has spread to other places in the body (metastatic). Abemaciclib is in a class of medications called kinase inhibitors. It is highly selective inhibitors of cyclin-dependent kinase 4 and 6, which are proteins involved in cell differentiation and growth. It works by blocking the action of an abnormal protein that signals cancer cells to multiply. Radioligand therapy uses a small molecule (in this case 177Lu-PSMA-617), which carries a radioactive component to destroys tumor cells. When 177Lu-PSMA-617 is injected into the body, it attaches to the prostate-specific membrane antigen (PSMA) receptor found on tumor cells. After 177Lu-PSMA-617 attaches to the PSMA receptor, its radiation component destroys the tumor cell. Giving abemaciclib before 177Lu-PSMA-617 may help 177Lu-PSMA-617 kill more tumor cells.