Pemetrexed USP 500mg is a chemotherapy drug used to treat some forms of cancer. Pemetrexed is a chemotherapy drug that is often used to treat non-small cell lung cancer and mesothelioma, a malignancy that affects the lining of the lungs, abdomen, or heart. It acts by interfering with cancer cells' capacity to divide and develop. As part of a complete cancer treatment strategy, it is frequently used in combination with other chemotherapy drugs. The treatment plan and dose will be determined by the type of cancer being treated as well as the patient's unique circumstances.