- A drug used alone or with other drugs to treat certain types of non-small cell lung cancer and malignant pleural mesothelioma. It is also being studied in the treatment of other types of cancer. Pemetrexed disodium stops cells from using folic acid to make DNA and may kill cancer cells. It is a type of antimetabolite and a type of antifolate. Also called Alimta, LY231514, and Pemfexy.