The explosion of new therapies for men with metastatic castration resistant prostate cancer (mCRPC) raises serious questions about the optimal sequencing of these new treatments as well as whether cross-resistance occurs between these drugs.

It was recently reported that chemotherapy with docetaxel (D) is not effective in in men who did not have a ? 50% PSA decline on prior Zytiga treatment (Ann Oncol 2012; 23(11):2943-7). To evaluate this, Azad etal. looked at the activity of D in men with mCRPC who had