Alisertib in Combination With Osimertinib in Metastatic EGFR-mutant Lung Cancer

This study is testing whether adding a drug called alisertib to the standard targeted therapy osimertinib can help patients with advanced lung cancer that has a specific genetic change (EGFR mutation) and has stopped responding to osimertinib alone. **You may be eligible if...** - You are 18 or older - You have stage IV non-small cell lung cancer with an EGFR mutation confirmed by a lab test - You are currently receiving osimertinib and your cancer has started growing again (or you are stable on first-line osimertinib) - You can swallow pills and your organ function is adequate - You are not pregnant and agree to use contraception **You may NOT be eligible if...** - You have had a bone marrow or organ transplant - You have bowel conditions that would prevent pill absorption - You have severe heart problems or an abnormal heart rhythm - You have uncontrolled brain metastases requiring steroids - You have another cancer diagnosed within the past 3 years (some exceptions apply) - Your cancer has a known resistance mutation better treated by another drug Talk to your doctor to see if this trial is right for you.