Purpose: We investigated the efficacy and toxicity of a novel oral 5-fluorouracil (5-FU) formulation (S-1), administered according to a tailored dose regimen.
Methods: S-1 was administered orally for 28 days, followed by 14 days of no treatment, in 23 patients who received a tailored dose of S-1, adjusted on the basis of individual creatinine clearance and body surface area. In 8 of the patients, pharmacokinetic study was performed on the 6 points on 7th day after S-1 administration.
Results: Of the 23 patients enrolled in this study, 2 (8.7 %) had a partial response and 14 (60.9 %) had stable disease. The disease control rate was 69.6 % (16/23) (95 % confidence interval, 50.8-88.4 %). Grade 3/4 hematologic and non-hematologic toxicities were minor. In the pharmacokinetic study group, the maximum plasma concentration (C (max)) and the area under the plasma concentration curve of 5-FU at all 6 points after administration of the tailored S-1 dose regimen were similar to the values reported in a previous study describing cancer patients with normal renal function who received a standard dose of S-1 (80 mg/m(2)/day).
Conclusions: Our results suggest that tailored S-1 monotherapy is safe and therapeutically useful as first-line treatment for elderly patients with advanced and recurrent non-small cell lung cancer.