S-1 (TeysunoTM) is a novel oral fluoropyrimidine derivative which offers a treatment option for patients with advanced non-small cell lung cancer (NSCLC). Currently, S-1 (TeysunoTM) is not approved for the first-line therapy for patients with advanced NSCLC, neither by the EMA nor by the FDA, but market authorization was granted by the EMA, as well as by several Asian countries, for the treatment of advanced gastric cancer in combination with cisplatin in March 2011.

One phase III trial investigated whether S-1 plus carboplatin was non-inferior to paclitaxel plus carboplatin in patients with advanced NSCLC. Within this trial, non-inferiority of S-1 was demonstrated for overall survival, but the selected non-inferiority margin of 1.33 was large. An improvement regarding Quality of Life in patients treated with S-1 was shown for some score, but not for the FACT-L. In terms of adverse events of higher grades, only thrombocytopenia was observed more often in the S-1 arm whereas other haematological side-effects occurred more frequently in the control group. The toxicity of S-1 can thus be regarded as acceptable.

However, the available evidence does currently not indicate that patients who qualify for more targeted treatment options will benefit from S-1. In addition, the price for S-1 which is currently unknown might potentially be higher than that for standard chemotherapeutics due to the oral application.