(Other name for: pralatrexate) or A drug used in the treatment of peripheral T-cell lymphoma (a fast-growing form of non-Hodgkin lymphoma). It is also being studied in the treatment of other types of cancer. FOLOTYN may block the growth of cancer cells and cause them to die. It is a type of dihydrofolate reductase (DHFR) inhibitor. Also called pralatrexate.