The primary objective in the Phase I Part is to evaluate feasibility of dose level DL1 to DL3 and defining a recommended dose (RD) for the Phase II part using the dose levels DL1-DL3 of the phase I part. The primary objective in the study’s Phase II Part is to evaluate the activity of the addition of temsirolimus to standard treatment on the disease progression-free survival in patients with castration resistant prostate cancer receiving first-line docetaxel chemotherapy.