Eligibility Criteria:
Inclusion Criteria:
* Histologically confirmed diagnosis of prostate adenocarcinoma
* PSA ≥ 10 ng/ml and two of the following 4 criteria:
* PSA ≥ 20 ng/ml,
* Gleason sum ≥ 8,
* cN1 (regional LN with a short axis length \>10mm by CT scan or MRI) or pathologically confirmed lymph nodes (pN1),
* cT3-T4 (by MRI or core biopsy) (i.e. If PSA≥ 20 ng/ml then only one of the other 3 risk factors is needed)
* M0 by standard imaging work-up (see chapter 6.1.1.1)
* Testosterone ≥ 200 ng/dl
* Adequate renal function: calculated creatinine clearance ≥ 50 mL/min (Appendix D) Magnesium and potassium within normal limits of the institution or corrected to within normal limits prior to the first dose of treatment.
* Patients with prolonged QT-intervals due to prescribed Class IA (quinidine, procainamide) or Class III (amiodarone, sotalol) antiarrhythmic medication must be carefully evaluated for GnRH-agonist or GnRH antagonist use, because these drugs may prolong the QT-interval.
* WHO Performance status 0-1
* Age ≥ 18 and ≤ 80 years
* Participants who have partners of childbearing potential must use adequate birth control measures, as defined by the investigator, during the study treatment period and for at least 3 months after last dose of study treatment. A highly effective method of birth control is defined as those which result in low failure rate (i.e. less than 1% per year) when used consistently and correctly
* Before patient registration/randomization, written informed consent must be given according to ICH/GCP, and national/local regulations.
Exclusion Criteria:
* Previous use of androgen deprivation therapy (ADT), antiandrogens. 5-alpha reductase inhibitors are allowed if interrupted for more than 6 months prior to entering the study
* History of severe untreated asthma, anaphylactic reactions or severe urticaria and/or angioedema.
* Hypersensitivity towards the investigational drug
* The following biological parameters :AST, ALT, total bilirubin, prothrombin time, serum albumin above upper level of normal range No severe hepatic impairment (Child Pugh C)
* History of gastro-intestinal disorders (medical disorder or extensive surgery) that may interfere with the absorption of the protocol treatment.
* History of pituitary or adrenal dysfunction
* Uncontrolled diabetes mellitus
* History of ulcerative colitis, Crohn's Disease, ataxia, telangiectasia, systemic lupus erythematous, or Fanconi anemia.
* Clinically significant heart disease as evidence myocardial infarction, or arterial thrombotic events in the past 6 months, severe or unstable angina, or New York Heart Association (NYHA) class III or IV heart disease or cardiac ejection fraction measurement of \< 50 % at baseline
* Coronary revascularization (PCI or multivessel CABG), carotid artery or iliofemoral artery revascularization (percutaneous or surgical procedure) within the last 30 days prior to entering the trial
* Certain risk factors for abnormal heart rhythms/QT prolongation: torsade de pointes ventricular arrhythmias (e.g, heart failure, hypokalemia, or a family history of a long QT syndrome), a QT or corrected QT (QTc) interval \>450 ms at baseline, or intake of medications that prolong the QT/QTc interval
* Uncontrolled hypertension (systolic BP ≥ 160 mmHg or diastolic BP ≥ 95 mmHg); patients with a history of hypertension are allowed provided blood pressure is controlled by anti-hypertensive treatment.
* Prior history of malignancies other than prostate adenocarcinoma (except patients with basal cell, squamous cell carcinoma of the skin), or the patient has been free of malignancy for a period of 3 years prior to first dose of study drug(s). Prior history of bladder cancer excludes the patient.
* Prior radical prostatectomy (TURP or suprapubic adenomectomy for benign prostatic hyperplasia is allowed)
* Prior brachytherapy or other radiotherapy that would result in an overlap of radiotherapy fields
* Any contraindication to external beam radiotherapy
* Patients with significantly altered mental status prohibiting the understanding of the study or with psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule or any condition which, in the opinion of the investigator, would preclude participation in this trial