AST2818 mesylate is primarily utilized in the field of oncology as a targeted therapy for non-small cell lung cancer (NSCLC). It functions as a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, specifically designed to combat tumors with EGFR mutations, including the T790M mutation, which is often associated with resistance to earlier generations of EGFR inhibitors. This compound is particularly effective in patients who have developed resistance to first- and second-generation EGFR inhibitors, offering a therapeutic option to extend progression-free survival. Additionally, it is being explored for its potential in treating other cancers where EGFR mutations play a significant role in tumor growth and progression. Clinical trials continue to assess its efficacy, safety, and potential combination with other anticancer therapies.