Pralatrexate, a new hope for aggressive T-cell lymphomas?

Aggressive T-cell lymphomas represent a particularly poor-prognosis subgroup of lymphomas. This is especially true for patients with recurrent or refractory disease who typically have a limited response to salvage therapy and an extremely poor overall survival. There is thus a strong need to develop potentially active drugs for these malignancies. Pralatrexate is a novel antifolate designed to have high affinity for the reduced folate carrier type 1. Preclinical and clinical studies have demonstrated that pralatrexate has significant activity against T-cell lymphomas.The dose-limiting toxicity for pralatrexate is mucositis,which could be abrogated with folic acid and vitamin B12 supplementation. Pralatrexate is now being evaluated in phase II clinical trials for the treatment of peripheral T-cell lymphoma, and in a phase I/II trial in combination with gemcitabine for the treatment of non-Hodgkin's lymphoma. Because of the limited therapies available for aggressive T-cell lymphoma, pralatrexate could secure a niche for the treatment of this condition, provided on going clinical trials and future phase III trials confirm the efficacy of the drug.