A Phase II Study of Androgen Deprivation Therapy With or Without Palbociclib in RB-Positive Metastatic Prostate Cancer

Patients will undergo exams, tests, and procedures to determine if they are eligible to participate. Subjects will be randomized to one of two groups. Patients randomized to Arm 1 - Patients will receive the LHRH agonist every 3 months. Patients will also take 50 mg. of bicalutamide by mouth every day. Bicalutamide comes in tablet form. This arm is broken down into periods of time called cycles, starting with cycle 1 then cycle 2, and so on.Each cycle is 28 days long. If randomized to Arm 2 - Patients will receive the LHRH agonist every 3 months. Patients will also take 50 mg. of bicalutamide by mouth every day. Patients will also take 125 mg. of Ibrance® daily for 21 days, and then will stop taking Ibrance® for 7 days. Patients will then begin taking Ibrance® again after 7 days off. Patients will keep repeating this cycle every 28 days. When the patient starts the first 28 day cycle that will be cycle 1, then cycle 2, and so on. During each cycle the patient will come in for routine and research tests and procedures for patient safety, to see how patients are doing, and for research purposes. The researchers will ask patients to complete a drug diary to track bicalutamide and Ibrance® administration. The total time of study participation depends on how a patient responds to the study medications. Patients may be on the study for a short period of time, such as a week, or for a longer period of time, such as a few years. Patients may continue on study treatment until one of the following: cancer progresses (gets worse); another illness or condition develops that prevents study participation; unacceptable side effects occur; drug is delayed more than 4 weeks; patient withdraws consent; the study doctor thinks the patient should stop; the patient does not follow researcher's instructions; the study is cancelled.