UFT plus oral leucovorin calcium (Orzel) and radiation in combined modality therapy: a comprehensive review

Abstract

5-fluorouracil (5-FU) has become the most commonly used drug in combination with radiation therapy. The recent availability of oral formulations of 5-FU in conjunction with the ability to modulate the anabolic and catabolic metabolism of 5-FU with leucovorin and dihydropyrimidine dehydrogenase (DPD) inhibitors, respectively, may provide a substantial improvement in the ease of administration and the efficacy of fluoropyrimidine therapy. Several oral fluoropyrimidines are under investigation. UFT (uracil:tegafur) plus oral leucovorin (Orzel) is the first oral DPD-inhibitory fluoropyrimidine. With daily administration, Orzel achieves similar concentrations of 5-FU obtained with continuous-infusion 5-FU. This paper summarizes the therapeutic rationale for Orzel and reviews the clinical experience with UFT and UFT/LV in combined modality therapy regimens.