Current evidence in support of the second-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor alectinib for the treatment of non-small cell lung cancer positive for ALK translocation

Treatment for advanced non-small cell lung cancer (NSCLC) depends on the molecular characteristics of the tumor. Mutations of the epidermal growth factor receptor (EGFR) gene are present in ~32% of Asians and ~7% of individuals of other ethnic groups with NSCLC (1), and rearrangements of the anaplastic lymphoma kinase (ALK) gene have been detected in ~3% to 5% of NSCLC tumors (2-4). The echinoderm microtubule-associated protein-like 4 (EML4) gene is the most common fusion partner of ALK in NSCLC, and the fusion gene exists in several variants with different breakpoints within EML4. NSCLC tumors that harbor ALK fusion genes are oncogene addicted and therefore usually sensitive to treatment with ALK tyrosine kinase inhibitors (ALK-TKIs).