The oral fluorouracil prodrugs

Discussed herein are selected oral fluorinated pyrimidines that are converted to 5-fluorouracil (5-FU) in vivo to exert antitumor activity. These agents include capecitabine (Xeloda), tegafur-uracil (UFT) plus leucovorin (Orzel), and S-1 (BMS247616). These agents offer the convenience of an orally administered therapy with potentially fewer toxic effects than conventional bolus regimens of 5-FU plus leucovorin. These oral agents provide prolonged 5-FU exposure at lower peak concentrations than observed with bolus intravenous administration of 5-FU and may confer pharmacoeconomic advantages by reducing administration costs and toxicity-related hospitalizations. These regimens also have the potential for improved therapeutic activity by achieving higher 5-FU concentrations in the tumor or by biochemically modulating 5-FU. Phase III trials in patients with advanced colorectal carcinomas are comparing the antitumor activity of these agents with that of intravenous 5-FU plus leucovorin.