Phase I-II clinical trial of thymidine, 5-FU, and PALA given in combination

Twenty-eight patients with advanced adenocarcinoma were treated with a combination of thymidine, 5-FU, and PALA. PALA (1 g/m2) was given on the first day, followed on the second day with 30 g of thymidine and 150-300 mg/m2 of 5-FU given simultaneously through two iv sites. Responses were seen in two of 17 patients (12%) with colorectal adenocarcinoma. One response was complete and one was partial. The gastrointestinal tract and CNS were the sites of dose-limiting toxic effects. Myelosuppression was observed only at 5-FU doses of 250 and 300 mg/m2.