The following rationale can be made for a Phase II trial to evaluate sunitinib malate (Sutent) for the therapy of progressive metastatic androgen-independent prostate cancer (AIPC) following prior docetaxel chemotherapy. Since most patients with metastatic AIPC following prior chemotherapy clinically progress rapidly, we believe that achieving a 30% freedom from clinical progression (PFS) (not including PSA progression) at 12 weeks represents biologically active therapy. Sunitinib malate (Sutent) represents a tolerable and convenient form of therapy with the potential for improving outcomes in AIPC.