Oral uracil-tegafur: an alternative to intravenous 5-fluorouracil?

The fluoropyrimidines have been used in the treatment of a number of tumour types over the past 40 years. Particular attention has focused on the use of 5-fluorouracil (5-FU) in colorectal cancer for which, until recently, there has been a lack of other effective chemotherapy. In an attempt to optimise the efficacy of fluoropyrimidines, a number of approaches have been used. These include alternative methods of iv. scheduling, the use of co-factors and the development of oral compounds. The aim of oral agents is to satisfy patient preference while maintaining the efficacy of sustained drug exposure seen with prolonged or continuous infusions of iv. 5-FU. One such oral compound is uracil-tegafur (UFT), which combines tegafur (ftorafur, a 5-FU prodrug) and uracil in a 1:4 molar ratio. UFT first entered Phase I trials in Japan over 20 years ago but has only recently received significant exposure in Phase II and III trials. Results from a number of Phase III studies in Europe and in the US are now becoming available. With UFT recently approved for colorectal cancer in many European countries, although not in the US, it is timely to review the current situation and future prospects for this agent.