Analyze the Predictive Value of Gene TMPRSS2-ETS in Response to Enzalutamide in Patients With Prostate Cancer

Inclusion Criteria:

* Patients aged 18 years and above, willing and able to provide written informed consent.
* Prostate adenocarcinoma with histological or cytological confirmation without neuroendocrine differentiation nor small cell characteristics
* Androgen deprivation therapy with GnRH analogs or bilateral orchiectomy (pharmacological or surgical castration). Patients without bilateral orchiectomy must follow a GnRH analog therapy during the trial.
* Testosterone serum level \<= 1,73 nmol/L (50 ng/dL) in screening visit.
* Patients under bisphosphonate therapy must have received stable doses for the last 4 weeks.
* Progression disease at inclusion, defined by one or more of the following three criteria during androgen deprivation therapy (according with the criterion nº 3): - PSA progression defined as two elevation of the PSA serum level with \>=1 week between each measure. Patients who have received an antiandrogen must present disease progression (\>=4 weeks since the last dose of flutamide or \>=6 weeks since the last dose of bicalutamide or nilutamide). PSA value in screening visit must be \>=2 μg/L (2 ng/mL). - Soft tissue progression defined by RECIST 1.1 criteria - Bone lesion progression defined by PCWG2 criteria, with two or more new lesions in a scintigraphy
* Metastatic disease with bone lesions detected by scintigraphy, or measurable soft tissue lesions by CT/MR. Patients with ganglionar disease will be suitable if they have at least one ganglionar lesion with smallest diameter \> 2,5 cm.
* Patients without previous cytotoxic chemotherapy for prostate cancer
* Patients without previous abiraterone acetate therapy for prostate cancer - - Asymptomatic patient or mild symptomatic about prostate cancer, (answer in the question nº 3 of the Brief Pain Inventory Short From \< 4) 11. ECOG = 0-1.
* Life expectancy of at least 6 months
* Patient must be able to swallow the investigation product and to follow the protocol requirements.
* Biomarker study informed consent

Exclusion Criteria:

* Active infection or other medical condition which, in the opinion of the investigator, would preclude participation in this trial.
* Known brain metastasis or leptomeningeal active involvement
* Other malignancy in the last five years, except non-melanoma skin cancer treated and resolved.
* Hematologic parameters: - Absolute neutrophil count \<=1500/μL - Platelet count \<100 000/μL - Haemoglobin \< 5,6 mmol/L (9 g/dL)
* Liver function: Serum bilirubin, SGPT/ALT or SGOT/AST \> 2,5 x ULN
* Renal function: Creatinine \>177 μmol/L (2 mg/dL).
* Serum albumin \<30 g/L (3,0 g/dL)
* History of epilepsy or other medical condition which could cause an epileptic crisis as syncope or transient ischemic attack in the last twelve months.
* Clinically significant cardiovascular disease.
* Known gastrointestinal (GI) disease that could interfere with the GI absorption.
* Significant surgery within 4 weeks before enrollment.
* Use of opioids to control cancer pain within 4 weeks before enrollment.
* Radiation therapy for treatment of the primary tumor in the last 3 weeks before enrollment
* Radiation therapy for treatment of metastases in the last two months
* Radionuclide therapy for treatment of bone metastasis
* Prior flutamide treatment within 4 weeks before enrollment
* Bicalutamide or nilutamide therapy within 6 weeks before enrollment
* 5-a reductase inhibitors, estrogen o cyproterone therapy within 4 weeks before enrollment
* Biologic therapy or other antitumoral drugs for the treatment of CRPC in the last 4 weeks
* History of cancer progression with ketoconazole
* Prior therapy or enrollment in a trial with an investigational product which blocks androgen synthesis (abiraterone, TAK-700, TAK-683, TAK-448) or blocks androgen receptors (ARN507, BMS 641988).
* Included in a previous trial with enzalutamide (MDV3100).
* Administration of an investigational drug in the last 4 weeks before enrollment
* Use of phytotherapy products which hormonal activity against prostate cancer or which reduce PSA levels, or systemic corticosteroids in a dose greater than the equivalent of prednisone 10mg/day, within 4 weeks before enrollment
* Hereditary fructose intolerance
* Any condition which, in the opinion of the investigator, would preclude participation in this trial.