Pemetrexed as Second-Line Therapy in Treating Patients With Hormone Refractory Prostate Cancer

Overview

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. This trial is designed to further assess the efficacy, safety, tolerability, and pharmacogenetics of pemetrexed as a single agent in subjects with HRPC whose disease has progressed following one prior taxane-based chemotherapy regimen for HRPC.

OUTLINE: This is a multi-center study. * Pemetrexed 500mg/m2 will be administered intravenously over approximately 10-minutes on Day 1 of a 21-day cycle. * Folic Acid (350-1000 mcg. PO daily) will be taken by patients to reduce toxicity. At least 5 daily doses of folic acid must be taken during the 7-day period preceding the first dose of pemetrexed, and dosing should continue during the full course of therapy and for 21 days after the last dose of pemetrexed. * Vitamin B12 (1000 µg) will be administered as an intramuscular injection during the week preceding the first dose of pemetrexed and every 3 cycles thereafter. Subsequent vitamin B12 injections may be given the same day as pemetrexed. Performance Status: Karnofsky Performance Status 70-100 Life expectancy \> 12 weeks Hematopoietic: * Absolute Neutrophil Count (ANC) \> 1500/mm3 * Platelet count \> 100,000/mm3 * Hemoglobin \> 9 g/dL Hepatic: * Bilirubin \< 1.5 X upper limit of normal (unless due to Gilbert's disease) * Alkaline phosphatase and Alanine Transanimase (ALT) (SGPT) \< 3 X upper limit of normal (ULN); may be \< 5 X ULN for patients with liver metastases. Alkaline phosphatase may be any value for patients with bone metastases. Renal: * Calculated creatinine clearance \>45 mL/min based on the standard Cockroft and Gault formula Cardiovascular: * No congestive heart failure requiring therapy or New York Heart Association (NYHA) class II or greater or active angina or known myocardial infarction within 12 months prior to study * No unstable angina, uncontrolled congestive heart failure, or unstable symptomatic arrhythmia requiring medication within 6 months prior to being registered for protocol therapy * Subjects with chronic atrial arrhythmia, i.e., atrial fibrillation, paroxysmal supraventricular tachycardia, or controlled hypertension are eligible Pulmonary: * Not specified