A Study to Evaluate the Combination of Platinum-pemetrexed Based Chemotherapy Plus Lorlatinib in ALK Positive Non-Small Cell Lung Cancer (NSCLC) With Exclusively Extracranial Disease Progression on Lorlatinib

This study tests whether adding standard chemotherapy (platinum plus pemetrexed) to lorlatinib can help patients with a type of lung cancer (ALK-positive non-small cell lung cancer) that has started growing outside the brain while on lorlatinib alone. **You may be eligible if...** - You are 18 or older - You have stage IV non-small cell lung cancer with an ALK gene change - Your cancer is progressing outside the brain while you are on lorlatinib - Your brain metastases (if any) are stable on lorlatinib - You are in good general health (ECOG 0-1) - Your cancer can be measured on scans **You may NOT be eligible if...** - Your cancer is progressing inside the brain - Your overall health is too poor for chemotherapy - You do not have the ALK genetic change in your tumor Talk to your doctor to see if this trial is right for you.