Pemetrexed Injections are used in chemotherapy (anti-cancer) medication for treating malignant pleural mesothelioma which is a cancer type that affects inside lining of chest cavity. Further, Pemetrexed alos finds usage in treating non-small cell lung cancer and comes from class of medication called antifolate antineoplastic agents. Available in form of a solution (liquid) that is injected into vein, the medicine works by blocking action of certain substance in body that can help in the further growth of cancer cells.