Docetaxel-based therapy has been shown to prolong survival as first-line therapy for patients with hormone refractory prostate cancer (HRPC), and has become the standard of care. The beneficial effects of any therapy in HRPC may be diverse and include reduction in tumor bulk (when measurable), reduction in prostate-specific antigen PSA, reduction in symptoms (particularly pain), or stabilization of disease. Clear reductions in tumor bulk or PSA may provide objective evidence of a treatment effect, and stabilization of disease may be just as clinically meaningful in patients who are actively progressing prior to starting therapy. Pemetrexed has shown a broad array of activity in many diseases that until now were thought to be non-responsive to chemotherapy in the second-line setting.