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

This study focuses on treating lung cancer in its terminal stage, specifically for patients who have a mutation in a protein called EGFR and cannot undergo surgery. These patients usually receive medications called gefitinib or erlotinib. The goal of this study is to find out if adding nicotinamide to these treatments can improve the patients' survival without the disease getting worse. This research is important as it could potentially enhance the current treatment approach for this type of lung cancer and meet the unmet needs of these patients. In this study, participants will receive either nicotinamide or a placebo (a pill with no active drug) along with their usual medication (gefitinib or erlotinib). This will continue for two years or until an event occurs. The size of the cancer will be monitored every two months through radiology. The study will evaluate the progression of the disease and the response to treatment using specific criteria. After observing 36 and 72 events, interim and final analyses will be conducted. The study will also assess the patients' quality of life and overall survival. Any adverse reactions to the treatment will be recorded and reported.