Treatment of ALK-Positive Non–Small Cell Lung Cancer

Crizotinib (Xalkori), the first inhibitor of both anaplastic lymphoma kinase (ALK) and c-Met receptor kinases, has been approved in the United States, Korea, and other countries for the treatment of ALK-positive non–small cell lung cancer (NSCLC). This approval came within just 4 years of the discovery of rearrangements in the ALK gene in a subset of patients with NSCLC. Oral crizotinib 250 mg twice daily showed excellent efficacy in patients with advanced ALK-positive NSCLC, with objective response rates of 61% and 51% in ongoing phase I and II studies, respectively. Objective response rates of current standard, single-agent, second-line therapies are less than 10%. Median progression-free survival was 10 months (95% confidence interval, 8.2–14.7) in the phase I study expanded cohort and has yet to be reached in the phase II study; progression-free survival with current therapies is less than 3 months. Crizotinib was well tolerated; grade 1/2 gastrointestinal toxicity and visual disturbances were the mos...