AZD3759 is primarily used in the treatment of non-small cell lung cancer (NSCLC), particularly in cases where the cancer has metastasized to the brain. It is an EGFR tyrosine kinase inhibitor designed to effectively cross the blood-brain barrier, targeting EGFR mutations that drive tumor growth. This makes it a promising option for patients with brain metastases who often have limited treatment choices. Its ability to inhibit tumor growth in both the central nervous system and peripheral tissues highlights its potential in improving outcomes for advanced NSCLC patients. Clinical trials have shown encouraging results in terms of tumor response and disease control, positioning it as a valuable therapeutic option in oncology.