Phase I evaluation of oral tegafur.

A phase I clinical study of tegafur (ftorafur) was conducted in 29 patients with various advanced solid tumors. To evaluate its efficacy and toxicity, the initial dose of 0.5 g/m2/day x 21 days at 3-week intervals was progressively increased to a maximum dose of 1.5 g/m2/day. Tegafur was administered orally in two or three divided doses. Diarrhea was the dose-limiting toxic effect and occurred more often in patients with abnormal pretreatment liver function. Nausea occurred in about one-half of the patients, but vomiting was infrequent. Skin rash and mucositis occurred in 10% and 7% of the patients, respectively. Neurologic toxic effects of tegafur were infrequent and mild. The hematologic toxicity of tegafur was minimal. Antitumor activity could be evaluated in 21 patients with measurable disease. One complete and three partial responses were observed in four of 17 patients who had adenocarcinoma of unknown primary origin. All responses occurred at doses greater tan or equal to 1.0 g/m2/day. The recommended dose of tegafur for this schedule of administration is 1.0 g/m2/day.