Late Friday, Aug. 26, the FDA announced it had granted accelerated approval of crizotinib for patients with advanced non-small cell lung cancer (NSCLC) who test positive for a specific gene mutation.Crizotinib, which was given the brand name Xalkori, has made news since results of a clinical study showed that it delayed tumor progression in patients with NSCLC who had a mutation in the ALK gene. The approval was based on two studies that showed a response rate (shrinkage or stabilization of the tumor) of 50 percent and 61 percent, respectively. Overall survival is still being evaluated, and a phase 3 trial is ongoing for Xalkori to receive full approval from the FDA. The mutated ALK (anaplastic lymphoma kinase) gene was first identified in lymphoma in 2004, then in lung cancer in 2007. The mutation actually occurs when parts of chromosome 2 breaks off and reattaches at a different location on a chromosome - fusing the ALK gene to the EML4 gene. In 2009, a review in the Journal of Thoracic Oncology showed the mutation to be a cause of about 4 percent of NSCLC cases. In less than a decade, researchers have identified a mutation, developed a drug to target it, tested the drug and succeeded in getting it approved. Although it only applies to a small population of lung cancers, the total number of patients who could benefit from Xalkori is estimated to be around 5,000 to 11,000 patients a year. "It's a good day for lung cancer patients, especially those with an EML4-ALK (mutation)," said Paul Bunn, MD, professor of medicine and the James Dudley chair in cancer research at the University of Colorado in Denver at a press briefing held on Aug. 30, who predicted that the recent approval marks a paradigm shift in the care and management of patients with lung cancer. Also approved is a companion diagnostic test called Vysis ALK Break Apart FISH Probe Kit that will identify patients who have the abnormal gene. While the mutation is more commonly seen in nonsmokers, there are no set clinical factors that identify patients who may have the mutation. "We feel that it is appropriate to test all lung cancer patients," Bunn said. The test will also prevent patients who would not respond to Xalkori from taking a drug that would not be beneficial – saving them time to try other therapies. Xalkori is a pill taken twice a day. Based on the approval, Xalkori is taken by itself, but there are studies looking at its effectiveness when combined with other drugs, including Tarceva (erlotinib), another targeted agent used in lung cancer. Side effects of Xalkori taken alone include diarrhea, vomiting, edema, constipation and vision disorders. It has also been associated with life-threatening pneumonitis (1.6 percent).The cost of Xalkori is estimated to be $9,600 a month, and the test will likely cost $1,500. Pfizer, the drug's maker, has launched First Resource, a program to help patients pay for the medication (877-744-5675; xalkori.com).