Abstract
The development of individualized therapies has become the focus of current oncology research. Precision medicine has demonstrated great potential for bringing safe and effective drugs to those patients stricken with cancer, and is becoming a reality as more oncogenic drivers of malignancy are discovered. The discovery of Epidermal Growth Factor Receptor (EGFR) mutations as a driving mutation in non-small cell lung cancer (NSCLC) and the subsequent success of the tyrosine kinase inhibitors (TKI) have led the way for NSCLC to be at the forefront of biomarker-based drug development. However, this direction was not always so clear, and this article describes the lessons learned in targeted therapy development from EGFR in NSCLC.