Study of Dose Escalation of Abiraterone Actetate in Prostate Cancer

Inclusion Criteria:

Step 1

* Male 18 years and older.
* Voluntary signed informed consents of the patient before any study-specific procedure.
* Histologically confirmed prostate adenocarcinoma.
* Presence of bone and/or soft-tissue and/or visceral metastases through CT scan, MRI, scintigraphy scan.
* Progressive disease assessed by PSA, CT scan, MRI or bone scan according to the PCGW3 criteria PSA progression is defined as a 25% or greater increase and an absolute increase of 2 ng/mL or more from the nadir, which is confirmed by a second value obtained 1 or more weeks later. Bone scan: at least two or more new lesions are seen on bone scan compared with a prior scan.
* Patient with no or moderate symptoms (no need for continuous opioid treatment)
* Effective castration confirmed by testosterone plasma level \< 50 ng/dL
* ECOG performance status: 0-2
* Life expectancy \> 3 months
* Patient affiliate to french social assurance
* Laboratory criteria within 14 days before inclusion:

  * SGPT and SGOT \< 5 fold the upper normal value
  * Kaliemia \> 3 mM
* Patient using an effective contraceptive method during treatment

Step2

* Patients receiving ABI 1000 mg/day + prednisone/prednisolone 10 mg once a day through step 1 for at least two months
* At least two measures of ABI plasma concentrations available within the first three months of treatment
* Mean of ABI concentration \< 8,5 ng/mL.
* Progressive disease occuring within 28 weeks following starting of ABI in the step 1. A progressive disease is assessed by PSA increase or bone scan according to PCWG3 criteria (15) or to CT scan according to RECIST 1.1 criteria (see § 2).
* Inclusion in step 2 must occur within 2 months following the first observation of cancer progression while in step 1.
* Patient using an effective contraceptive method during treatment

Exclusion Criteria:

Step 1

* Pure small cell carcinoma of the prostate or predominant histology of neuro-endocrine carcinoma.
* Confirmed brain and/or leptomeningeal metastases
* Previous treatment with docetaxel or any other anticancer treatment for castration-resistant prostate carcinoma (previous docetaxel for hormone-sensitive metastatic disease is allowed)
* Previous treatment with ABI or any other 17 B hydroxylase inhibitor or enzalutamide
* Treatment with first-generation antiandrogen (ciproterone acetate, bicalutamide, flutamide, nilutamide) performed on the day of baseline or within previous four weeks, due to possible anti-androgen withdrawal response. (This criterion does not apply for subjects, who have never responded to anti-androgen treatment).
* Patient co-morbidities:

  * Patients with the following hereditary diseases: galactose hypersensitivity, Lapp lactase deficiency.
  * Cirrhosis Child-Pugh B or C
  * Active or symptomatic viral hepatitis
  * Heart failure stage NYHA III or IV
  * Cardiac arythmia, heart failure stage NYHA II, ischemic cardiopathy or uncontroled hypertension, except if left ventricular ejection fraction is \> 50%
  * Patients with left ventricular ejection fraction (LVEF) \< 50%
  * Evidence of any other disease, metabolic dysfunction, physical examination finding or laboratory finding giving reasonable suspicion of a disease or condition that contraindicates the use of an investigational drug or puts the patient at high risk for treatment related complications.Prior or concurrent malignant disease in complete remission for less than 3 years, except T1N0 vocal cord carcinoma, basal or squamous cell skin carcinoma and in situ transitional cell bladder carcinoma
* Limitation of the patient's ability to comply with the treatment or to follow-up the protocol.

Step 2 Grade 3-4 toxicities related to ABI. In case of persistent grade 2 toxicity, inclusion in step 2 must be discussed in a case by case basis with the study coordinating Investigator.

* All non-inclusion criteria for step 1 applied
* Patient who is not adherent to ABI treatment at the investigator opinion
* Patient with a symptomatic and/or visceral tumor progression that would be an indication to start chemotherapy immediately according to the opinion of the investigator