- Tumor biopsy: For Cohort 1 and Cohort 2, a fresh tumor sample after progression on erlotinib, gefitinib, afatinib, or another EGFR- Tyrosine kinase inhibitors (TKI) and before starting in this study is required; in addition, archival samples obtained pre-EGFR-TKI are required (if available). For Cohort 3, subjects who are crizotinib/ROS1 inhibitor naive will be required to provide a copy of the genetic report showing ROS1 positive mutation and archival tissue if available; subjects with ROS1 fusions who progressed on crizotinib/ROS1 inhibitor will be required to provide a copy of the genetic report showing ROS1 positive mutation and a fresh biopsy.