Phase 2 Study of S-1 as 2nd Line Therapy in Advanced Non-Small Cell Lung Cancer

Advanced non-small cell lung cancer is relatively unresponsive to chemotherapy. This is true for the nucleoside analogue gemcitabine, with a response rate of approximately 10%, as well as for 5-fluorouracil (5-FU). Even when gemcitabine is combined with other chemotherapeutic drugs or biological agents, the overall tumor response rate remains basically unchanged. S-1 is a new generation oral fluoropyrimidine that combines Tegafur (5-fluoro-1-(tetrahydro-2-furanyl)-2,4(1H,3H)-pyrimidinedione \[FT\]), an oral prodrug of 5-FU, with two modulators, Gimeracil (5-chloro-2,4-dihydroxypyridine \[CDHP\]), which inhibits 5-FU degradation by dihydropyrimidine dehydrogenase (DPD) inhibition, and Oteracil potassium (Oxo), which inhibits 5-FU phosphorylation in the digestive tract. This combination of 3 compounds is designed to achieve enhanced antitumor activity while decreasing gastrointestinal toxicity. This is an open-label, multicenter, single-arm, 3-stage, Phase 2 study evaluating the efficacy and safety of single agent S-1 as 2nd line therapy for patients with advanced NSCLC. The 3 stages of this study correspond to a futility stage (stage 1), a decision stage (stage 2), and a stage for improvement of precision of ORR (stage 3).