Nicotinamide Add-on Therapy for EGFR Mutated Lung Cancer Patients on Gefitinib or Erlotinib

The standard therapy to the EGFR (epidermal growth factor receptor) mutation positive non-small-cell lung cancer patients who are not eligible to operation is to administer EGFR-TKIs (tyrosine kinase inhibitors, gefitinib or erlotinib). To determine the effectiveness of nicotinamide on lung cancer, nicotinamide or placebo tablet will be co-administered with gefitinib or erlotinib for two years until the event or censoring occurs. The stratified block randomization was designed with 3 covariates (EGFR mutation status, kind of EGFR-TKI, ECOG (Eastern Cooperative Oncology Group) performance status score variation). The size of lesions will be checked every other months by radiology. PD (progressive disease) will be assessed according to RECIST(Response Evaluation Criteria in Solid Tumors)1.1. After observing 36 events, an interim analysis of hazard ratio by Cox proportional hazard regression will be performed. The final analysis will be done by the same protocol after observation of 72 events. The significance level of the interim and final analysis were set to 0.0075 and 0.0209 respectively. Response rate, quality of life (measured by 10 questions at every visit), and overall survival will be analysed together. All other adverse reactions will be analysed and reported, if there.