Wu YL, et al. - In this phase II, open-label, single-arm trial, the efficacy and safety of crizotinib, an inhibitor of anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1), and MET, has shown marked antitumor activity in a small expansion cohort of patients with ROS1-positive advanced non–small-cell lung cancer (NSCLC) from an ongoing phase I study, was assessed in East Asian patients with ROS1-positive (assessed through validated AmoyDx assay at three regional laboratories) advanced NSCLC who had received three or fewer lines of prior systemic therapies. Objective response rate (ORR) by independent radiology review (IRR) was examined. Crizotinib was shown to provide clinically meaningful benefit and elicit durable responses in this patient population. With good tolerability, crizotinib had a safety profile consistent with previous reports.