Open randomized study of previously untreated metastatic prostate cancer patients comparing intermittent to continuous treatment with cyproterone acetate. Evaluation of step-up therapy adding an LHRH agonist upon progression is included.

The primary aim of this study is to investigate whether intermittently administered CPA is superior to continuously administered CPA with respect to:

1. time to PSA progression after at least three months of continuous CPA and/or

2. time to clinical disease progression after at least three months of continuous CPA and

3. quality of life and

4. the ratio and length of time without anti-androgenic treatment in the intermittent arm of the trial.


Secondary endpoints are:

1. time to secondary PSA progression after castration and/or

2. time to clinical disease progression after castration and

3. time to disease specific mortality

4. overall mortality (all causes).

The study is an open-label, multi-centre trial, taking place in several European countries. Before being assigned to either treatment group, the patients will receive continuous oral CPA treatment of 300 mg/day in a preliminary phase (pre-phase) lasting 3-6 months, depending on their PSA response. After the pre-phase, an evaluation of hormone sensitivity will be done and patients will be stratified in good, moderate and non-responders. Non responders (stable PSA or PSA increase in the pre-phase) are withdrawn from the study.

Intermittent androgen deprivation using CPA oral monotherapy improves the overall quality of life while achieving similar control of tumour growth to that attained by continuous CPA treatment.

CPA 300 mg/day continuous versus CPA 300 mg/day intermittent.