Primary Objective:

• To compare the continuation of treatment with docetaxel versus switching to cabazitaxel regarding the time to PSA (Prostatic Specific Antigen) progression (TTP-PSA), in patients with Castration-Resistant Prostate Cancer (CRPC) that, after four cycles of docetaxel, have minor PSA response (defined as a reduction between 1% and 49%) or increase of up to 24% in PSA levels.

Secondary Objectives:

• PSA response rate
• Overall survival (OS)
• Incidence of Adverse Events

Screening: 21days (+7 days) Treatment: until PSA progression Post-treatment Follow-up: 2 years

Inclusion criteria :

• Documentation of histological prostate cancer;
• Patients with metastatic CRPC (Castration-Resistant Metastatic Prostate Cancer) who progressed with hormone deprivation, including the withdrawal of antiandrogen-class drugs for at least 4 weeks, and 6 weeks for bicalutamide or if documented that PSA did not decrease during 3 months of this therapy;
• Documentation of metastasis by imaging (computerized tomography [CT], magnetic resonance imaging [MRI] or bone scan), in patients with PSA < 20 ng/mL at the time of inclusion
• Provide minor PSA response (characterized by a reduction between 1% and 49%) or increase up to 24% in PSA levels, in relation to the value measured before starting docetaxel therapy, measured at least 7 days after the fourth cycle of docetaxel;
• Patient has received 4 cycles of docetaxel at a dose of 75 mg/m2 ;
• ECOG performance status of 0 or 1;
• Marrow, liver and renal function within acceptable values;
• PSA ≥ 2 ng/mL;
• Testosterone level ≤ 50 ng/dL (for patients with no prior history of orchiectomy).

Exclusion criteria:

• Prior use of chemotherapy, except for docetaxel for four cycles;
• Documented disease progression during treatment with docetaxel (first 4 cycles);
• Patients with metastases resulting in neurological damage;
• Inability to continue receiving gonadotropin-releasing hormone agonists in patients with no prior history of orchiectomy;
• Use of recombinant methionyl human granulocyte-colony stimulating factor non-glycosylated (G-CSF) in the 24 hours preceding baseline;
• Any other current neoplasia or over the past 5 years, except for basal cell skin carcinoma or squamous skin cell carcinoma;
• Known seropositivity for HIV (Human immunodeficiency Virus );
• Concomitant diseases, such as significant neurological or psychiatric disease; uncontrolled hypercalcemia or any other serious comorbidity;
• Hypersensitivity or allergy to any of the study treatments.

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.