Osimertinib In EGFR Mutant Lung Cancer

This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational drug to learn whether the drug works in treating a specific disease. "Investigational" means that the drug is being studied. This research study is studying a targeted therapy as a possible treatment for Non-Small Cell Lung Cancer (NSCLC) with an EGFR (epidermal growth factor receptor) genetic mutation. The EGFR gene produces a protein that helps cells divide. Specific changes or a mutation in the genetic information causes abnormal cell division and can lead to lung cancer. Patients who have NSCLC with an EGFR gene mutation can be treated by drugs called EGFR tyrosine kinase inhibitors (EGFR TKIs). They may stop (or "inhibit") the effect of the mutation in the EGFR gene. \- Osimertinib has been approved by the FDA (the U.S. Food and Drug Administration) for this disease.