[Phase II study of a new fluorinated pyrimidine, ethyl (+/-)-t-6-butoxy-5-fluoro-2, 4-dioxohexahydropyrimidine-r-5-carboxylate (TAC-278)].

A Phase II study of a new fluorinated pyrimidine (TAC-278) was performed in 14 institutions from May 1980 to April 1981. 400-1200 mg of TAC-278 was orally administered in 2 to 4 divided doses every day for more than 4 weeks. Selection of patients and evaluation of clinical response were done according to the criteria for "Evaluation of Clinical Effects of Chemotherapy on Solid Tumors" by Koyama and Saito. A total of 188 patients were entered in the study and 96 of them were evaluable. Partial responses were observed in 9.4% (9/96) of the evaluated cases. Stomach cancer and colorectal cancer showed partial responses in 10.8% (4/37) and 20% (5/25), respectively. As for side effects, slight gastrointestinal symptoms (loss of appetite, nausea and vomiting etc.) were found in 24% and CNS-symptoms such as dizziness and disorientation were observed in approximately 8% of the patients.