Pemetrexed is a chemotherapy drug. Its indications are the treatment of pleural mesothelioma and non-small cell lung cancer. In February 2004, the Food and Drug Administration approved pemetrexed for treatment of malignant pleural mesothelioma, a type of tumor of the lining of the lung, in combination with cisplatin for patients whose disease is either unresectable or who are not otherwise candidates for curative surgery. In September 2008, the FDA granted approval as a first-line treatment, in combination with cisplatin, against locally advanced and metastatic non-small cell lung cancer (NSCLC) in patients with non-squamous histology.

Pemetrexed is also recommended in combination with carboplatin for the first-line treatment of advanced non-small cell lung cancer. However, the relative efficacy or toxicity of pemetrexed-cisplatin versus pemetrexed-carboplatin has not been established beyond what is generally thought about cisplatin or carboplatin doublet drug therapy.

Pemetrexed is chemically similar to folic acid and is in the class of chemotherapy drugs called folate antimetabolites. It works by inhibiting three enzymes used in purine and pyrimidine synthesis—thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT). By inhibiting the formation of precursor purine and pyrimidine nucleotides, pemetrexed prevents the formation of DNA and RNA, which are required for the growth and survival of both normal cells and cancer cells.

Formal Chemical Name (IUPAC)
(4-(2-(2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)ethyl)benzoyl)-L-glutamic acid

References

https://en.wikipedia.org/wiki/Pemetrexed