Cisplatin, Pemetrexed, and Imatinib Mesylate in Malignant Mesothelioma

Primary Objective: * To determine the maximum tolerated dose of the combination of cisplatin, imatinib mesylate, and pemetrexed in metastatic malignant mesothelioma. Secondary Objectives: * To explore the biologic effects of cisplatin, imatinib mesylate, and pemetrexed on tumor tissue by: * histologic analysis of biopsy tissue * by non-invasive assessments of tumor vascularity performed before, during and after treatment * electron microscopy analysis of endothelial cell architecture after patient treatment with imatinib mesylate * To explore the effects of cisplatin, imatinib mesylate, and pemetrexed on surrogate markers in serum. * To assess the rate of response to therapy. * To determine the doses of the combination regimen of cisplatin, imatinib mesylate, and pemetrexed that enables de-phosphorylation of platelet derived growth factor receptor (PDGF-R) on malignant mesothelioma tumor cells. * To determine the pharmacokinetic interaction between agents in this combination regimen.