Pralatrexate, sold under the brand name Folotyn, is a medication used for the treatment of relapsed or refractory peripheral T-cell lymphoma (PTCL).

[4][5] Pralatrexate is indicated for the treatment of people with relapsed or refractory peripheral T-cell lymphoma (PTCL).

[3] Research on this class of drugs began in the 1950s at SRI International, where scientists were focused on developing new chemotherapies and antifolates that would be effective against tumor cells.

[6] In the late 1970s, researchers at Memorial Sloan Kettering Cancer Center discovered that cancerous cells take in natural folate through a protein identified as plasma membrane transporter (now referred to as "reduced folate carrier type 1" or "RFC-1").

[5][4] Some oncologists, patient groups, and insurance companies criticized the cost of $30,000 a month or more, which could reach a total of $126,000 during a course of treatment.