Pralatrexate (Folotyn)

T-cell lymphoma accounts for 10% to 15% of all cases of non-Hodgkin lymphoma in the United States (approximately 5000 to 6000 cases a year). Peripheral T-cell lymphoma (PTCL) comprises a subgroup of rare and aggressive non-Hodgkin lymphomas that develop from T cells in different stages of maturity outside of the thymus. Cutaneous T-cell lymphoma is a subgroup that falls within the T-cell lymphoma population but is classified differently than other PTCLs. Most cases of CTCL are considered indolent and can often be treated with less aggressive therapies. Eight percent to 55% of CTCL cases undergo transformation, and once this transformation occurs, the disease acts similarly to other PTCLs and its classification changes to that of a PTCL. Transformed CTCL requires aggressive systemic therapy. Pralatrexate is the first Food and Drug Administration-approved drug for relapsed and refractory PTCL and has also gained compendia approval for treatment of CTCL. Pralatrexate is an antifolate chemotherapeutic inhibitor of dihydrofolatereductase. It has a high affinity for the one carbon-reduced folate carrier, which leads to better cellular internalization of the drug and has a greater antitumor effect than methotrexate. Several clinical trials have been conducted to evaluate the use of this drug in PTCL and other malignancies such as non-small cell lung cancer. This review offers focused information for dermatologists about pralatrexate and its use as a novel treatment for relapsed or refractory PTCL.