Phase II study of crizotinib in east Asian patients (pts) with ROS1-positive advanced non-small cell lung cancer (NSCLC).

9022Background: Approximately 1–2% of NSCLCs harbor a rearrangement of the ROS1 gene, an oncogene for which screening is difficult due to its low incidence. Crizotinib, an inhibitor of anaplastic lymphoma kinase (ALK), ROS1, and MET, showed marked antitumor activity in ROS1-positive advanced NSCLC (Shaw, N Engl J Med 2014). In the present study, we assessed the antitumor activity and safety of crizotinib in East Asian pts with ROS1-positive advanced NSCLC. Methods: In this ongoing open-label, single-arm phase II study (NCT01945021), pts with ROS1-positive, ALK-negative advanced NSCLC who had received ≤ 3 lines of prior systemic therapy were administered crizotinib at a starting dose of 250 mg BID. Treatment was continued until RECIST-defined progression (determined by independent radiology review [IRR]), unacceptable toxicity, or withdrawal of consent, or at the investigator’s discretion for ongoing clinical benefit. The primary endpoint was ORR by IRR. Results: Between September 2013 and January 2015, 12...