Targeted therapies for ROS1-rearranged non-small cell lung cancer.

ROS1 gene fusions account for approximately 1-2% of all cases of non-small cell lung cancer (NSCLC). Similarly to anaplastic lymphoma kinase (ALK)-positive NSCLC, patients with ROS1+ NSCLC tend to have minimal smoking and be of the female sex. In most cases, adenocarcinoma is the dominant histology. The ROS1 gene has homology to ALK and this structural similarity formed the basis for utilizing ALK inhibitors for ROS1+ NSCLC. On the basis of impressive progression-free survival of 19.2 months from the PROFILE 1001 trial, crizotinib obtained Food and Drug Administration (FDA) approval as first-line therapy for treatment of ROS1+ NSCLC. Since then, there has been a growing appreciation of the incidence of brain metastases in ROS1+ NSCLC and rates of central nervous system progression on crizotinib. Additionally, appreciation of novel resistance mechanisms to crizotinib has led to the development of newer tyrosine kinase inhibitors (TKIs). In this review, we highlight known and emerging TKIs for the management of ROS1+ NSCLC.