works as an antifolate. It interferes with the folate metabolism
in the body, and thus inhibits the synthesis of folate-dependent
enzymes which are needed for the formation of some nucleotides,
the precursors of the genetic material. By preventing the formation
of these nucleotides, the drug prevents the formation of the genetic
material (DNA and RNA) required for the growth of both normal
and cancer cells. Pemetrexed is administered as a solution via
injection into a vein and is usually given once every 21 days.
It is available in 500 mg vials of lyophilized powder. Known side
effects include nausea and vomiting, fatigue, shortness of breath,
anorexia, anemia, chest pain, fever, infection, edema, and rash.
Pemetrexed as a single-agent is indicated for the treatment
of patients with locally advanced or metastatic non-small cell
lung cancer after prior chemotherapy. The effectiveness of Pemetrexed
in second-line NSCLC was based on the surrogate endpoint, response
rate. There are no controlled trials demonstrating a clinical
benefit, such as a favorable survival effect or improvement of
Pemetrexed in combination with the chemotherapy agent cisplatin
is used in treatment of malignant pleural mesothelioma when the
disease is unresectable or somehow not a good candidate for surgery.