Patient description: The patient is a 55-year-old man who was recently diagnosed with Parkinson's disease. He is complaining of slowness of movement and tremors. His disease is ranked as mild, Hoehn-Yahr Stage I. His past medical history is significant for hypertension and hypercholesterolemia. He lives with his wife. They have three children. He used to be active with gardening before his diagnosis. He complains of shaking and slow movement. He had difficulty entering through a door, as he was frozen and needed guidance to step in. His handwriting is getting smaller. He is offered Levodopa and Trihexyphenidyl. He is an alert and cooperative man who does not have any signs of dementia. He does not smoke or use any illicit drugs.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Prostate Adenocarcinoma Each patient must meet all of the following to be enrolled in the study Age >/= 18 years and are capable of giving informed consent. Voluntary written informed consent before performance of any study-related procedure not part of normal medical care, with the understanding that consent may be withdrawn by the subject at any time without prejudice to future medical care Patients must have a pathologically confirmed diagnosis of prostate adenocarcinoma. Features of neuroendocrine phenotype are allowed Patients must have evidence of castration resistant metastatic disease and eligible for Enzalutamide per standard guidelines. Castration resistant non-metastatic disease is allowed in phase I study if subject is candidate for Enzalutamide Patients must have and ECOG performance status of ≤ 2.(appendix D) Patients must be on continuous LHRH agonist or antagonist treatment or surgically castrated with castrate levels of testosterone (< 20 ng/dl) Any number of prior chemotherapy regimens are allowed. Chemotherapy naïve patients are allowed If patient is already on Enzalutamide at a dose of 160mg daily, he is allowed if he can have baseline image and PSA within 1 month of the start of entinostat Patients may have had androgen synthesis inhibitors or other investigational drugs. Patient must have discontinued flutamide or nilutamide or other AR targeted agents (including abiraterone) for at least 4 weeks and bicalutamide for at least 6 weeks prior to day 1 of treatment Patients receiving treatment with bisphosphonates or denosumab must remain on treatment during the study  Patients meeting any of the following are not to be enrolled in the study Patient was treated and discontinued Enzalutamide previously for any reason Major surgery within 28 days or serious infection requiring IV antibiotics within 14 days preceding the first dose of study treatment Patient has received other investigational drugs within 14 days before enrollment Known GI disease or GI procedure that could impact drug absorption in the upper bowel, or tolerance of Entinostat. Examples but are not limited to partial gastrectomy, small bowel resection, pancreatectomy, malabsorption or celiac disease Ongoing nausea or vomiting of any severity without improvement after appropriate treatment > Grade 1 diarrhea, not controlled with appropriate treatment History of uncontrolled sleep apnea syndrome and other conditions that could result in excessive daytime sleepiness, such as severe chronic obstructive pulmonary disease requiring supplemental oxygen Clinical and/or radiographic evidence of cerebral metastases. However, patients who have a history of central nervous system (CNS) metastasis but who have no radiographic or clinical evidence of residual tumor (eg, following complete surgical resection or stereotactic radiosurgery) are not excluded from participation in this study