This phase I/II trial characterized the tolerability, safety, and antitumor activities of unecritinib, a novel derivative of crizotinib and a multi-tyrosine kinase inhibitor targeting ROS1, ALK, and c-MET, in advanced tumors and ROS1 inhibitor-naive advanced or metastatic non-small cell lung cancer (NSCLC) harboring ROS1 rearrangements. The gene discussed is ALK; the disease is non-small cell lung carcinoma.