Inclusion Criteria:

- Has a histologically confirmed adenocarcinoma of the prostate, for which endocrine
therapy is indicated

- Has a current tumour, nodule and metastasis (TNM) staging within 12 weeks prior to
treatment start and, if clinically indicated a bone scan

- Has a PSA level meeting one of these criteria:

1. For treatment-naïve patients: Screening PSA level should be ≥2 ng/mL.

2. For patients with recurrence after radical prostatectomy: Patients should have a
serum PSA increase of ≥0.2 ng/mL from the previous test on two consecutive
measurements

3. For patients with recurrence after radiotherapy or cryotherapy: Patients should
have a serum PSA (two measurements) to be >2 ng/mL higher than a previously
confirmed PSA nadir

- Has a screening serum testosterone level above the lower limit of normal range in an
elderly male population, globally defined as >150 ng/dL

- Has an Eastern Cooperative Oncology Group score of ≤2

- Has a life expectancy of at least one year

Exclusion Criteria:

- Has had previous or is currently under hormonal management of prostate cancer

- Is considered to be a candidate for curative therapy i.e. radical prostatectomy or
radiotherapy during the trial period

- Has a history of bilateral orchiectomy, adrenalectomy, or hypophysectomy

- Has a marked baseline prolongation of QT/QTcF interval (e.g. repeated demonstration
of a QTcF interval >450 ms)

- Has a history of risk factors for Torsade de Pointes ventricular arrhythmias (e.g.
heart failure, hypokalemia, or family history of Long QT Syndrome)

- Has a previous history or presence of another malignancy, other than prostate

- Currently receiving chronic treatment with intramuscular medication injected into the
ventrogluteal or dorsogluteal muscle

- Has received an investigational drug within the last 28 days preceding the Screening
Visit or longer if considered to possibly influence the outcome of the current trial