ETC-206 is a potent and selective inhibitor of ALK (anaplastic lymphoma kinase), primarily investigated for its use in the treatment of non-small cell lung cancer (NSCLC) that harbors ALK gene rearrangements. It is designed to target both ALK fusion proteins and resistant mutants that emerge after treatment with earlier-generation ALK inhibitors. Due to its ability to cross the blood-brain barrier effectively, ETC-206 shows strong activity against brain metastases, a common complication in ALK-positive NSCLC patients. Its development focuses on overcoming resistance mutations such as G1202R and F1174L, making it a candidate for patients who have progressed on other ALK-directed therapies. Preclinical studies indicate high selectivity and sustained target inhibition, supporting its evaluation in clinical trials for advanced solid tumors, especially those driven by ALK alterations.