PLX3397, Radiation Therapy, and Antihormone Therapy in Treating Patients With Intermediate- or High-Risk Prostate Cancer

This phase I trial studies the side effects and best dose of multitargeted tyrosine kinase inhibitor PLX3397 (PLX3397) when given together with radiation therapy and antihormone therapy in treating patients with prostate cancer that is at intermediate or high risk of spreading. Multitargeted tyrosine kinase inhibitor PLX3397 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth, and may also help the radiation therapy work better. Radiation therapy uses high-energy x-rays to kill tumor cells. Androgens can cause the growth of prostate cancer cells. Antihormone therapy, such as leuprolide acetate, goserelin acetate, or degarelix, may lessen the amount of androgens made by the body. Giving multitargeted tyrosine kinase inhibitor PLX3397 with radiation therapy and antihormone therapy may be a better treatment for prostate cancer.