Used in the treatment of non-small cell lung cancer (NSCLC) with EGFR mutations, particularly effective against T790M resistance mutation. Designed to cross the blood-brain barrier, making it effective for treating brain metastases. Shows high selectivity for mutant EGFR over wild-type, reducing skin and gastrointestinal toxicities commonly seen with other EGFR inhibitors. Currently investigated in clinical trials for advanced or metastatic NSCLC patients who have progressed on prior EGFR-targeted therapies.