Inclusion Criteria:

Age > 18 years. Histologically confirmed prostate adenocarcinoma. ECOG ≤ 2. Evidence of
metastatic disease by the presence of documented locoregional or distant metastases on CT
scan of the abdomen and/or pelvis, or bone scintigraphy.

Patients who have had disease progression during or after prior docetaxel chemotherapy
regimen, defined as:

Progressive measurable disease : At least a 20% increase in the sum of the longest
diameters of measurable lesions over the smallest sum observed -or- the appearance of one
or more new measurable lesions as assessed by CT scan. Soft tissue disease progression
defined by modified RECIST 1.1 criteria (baseline lymph node size must be ≥ 2.0 cm to be
considered target or evaluable lesion).

OR Bone Scan Progression: appearance of 2 or more new lesions on bone scan. OR Increasing
serum PSA level: Two consecutive increases in PSA levels documented over a previous
reference value obtained at least one week apart are required. If the third PSA value is
less than the second, an additional fourth test to confirm a rising PSA is acceptable. A
minimum starting value of 2.0 ng/mL is required for study entry.

NOTE: Androgen ablative therapy may have included either medical or surgical castration.

At least one prior chemotherapy regimen of docetaxel. At least 28 days had to have elapsed
between the withdrawal of antiandrogens and enrolment, except LH-RH agonist therapy that
must be continued throughout this study for patients who were already treated by it.

Hormonal castration confirmed biologically (testosterone < 0.5 ng/ml). Patient with
adequate organ function10. Patient able to swallow abiraterone acetate whole as a tablet.

Information delivered to patient and informed consent signed by the patient or legal
representative.

Patient affiliated with a health insurance system.

Exclusion Criteria:

Patients already treated with abiraterone acetate. Known hypersensitivity or allergy to
abiraterone or any of the excipients Patients suffering from severe or moderate hepatic
impairment (Child-Pugh Class B or C), active or symptomatic viral hepatitis or renal
impairment.

Any radiation within 28 days prior to study entry. Patient with central nervous system
(CNS) metastasis or with history of CNS metastasis.

Patient treated for a cancer other than prostate cancer, with the exception of basal cell
carcinoma, within the past 5 years.

Treatment on another therapeutic clinical trial within 28 days before enrolment Prior
treatment with novel hormonal agents including enzalutamide, orteronel, ARN509, EPI100 and
novel non hormonal treatments including cabozantinib, alpharadin.

Patients with uncontrolled hypertension, heart disease clinically significant (such as
myocardial infarction or recent arterial thrombotic events, severe or unstable angina,
heart failure class III-IV NYHA (appendix 5) or with a measurement of the cardiac ejection
fraction <50%), within 6 months of randomization.

Any significant concurrent medical illness that in the opinion of the Investigator would
preclude protocol therapy.

Permanent contraindication to corticosteroids. Patients who have partners of childbearing
potential who are not willing to use refusing 2 methods of birth control with adequate
barrier protection during the study and for 13 weeks after last study drung
administration.

Patient with history of poor compliance or current or past psychiatric conditions or
severe acute or chronic medical conditions that would interfere with the ability to comply
with the study protocol.

Patient enables to give informed consent.