Brigatinib is primarily used in the treatment of non-small cell lung cancer (NSCLC), specifically for patients who have developed resistance to other treatments. It is particularly effective in cases where the cancer has an ALK (anaplastic lymphoma kinase) mutation. The drug works by inhibiting ALK and other proteins that contribute to the growth and spread of cancer cells. It is often prescribed after the failure of crizotinib, another ALK inhibitor, due to its ability to target mutations that cause resistance. Brigatinib is administered orally and is known for its ability to penetrate the central nervous system, making it effective in treating brain metastases associated with NSCLC. Its use is supported by clinical trials demonstrating improved progression-free survival and overall response rates in patients with ALK-positive NSCLC.