The gist: The drug Xalkori (aka crizotinib) could help treat people with advanced non-small cell lung cancer (NSCLC) whose tumors have mutations known as ROS1-rearrangement. (Tumor mutations can be detected by molecular testing.) Xalkori is already known to help some people with tumor mutations in the ALK gene.
“In a study reported in The New England Journal of Medicine, Shaw et al found that crizotinib (Xalkori) produced a high response rate in patients with ROS1-rearranged non–small cell lung cancer (NSCLC).
“Chromosomal rearrangements in ROS1, which encodes the proto-oncogene receptor tyrosine kinase ROS1, define a distinct molecular subgroup in NSCLC. In addition to inhibiting ALK, crizotinib inhibits ROS1 and MET. As noted by the investigators, oncogenic ROS1 fusions may account for approximately 15,000 of the worldwide 1.5 million new cases of NSCLC each year. ALK and ROS1 rearrangements are infrequently found within the same tumor. Both are more common in patients with a history of never or light smoking and in adenocarcinoma.
“The investigators concluded: ‘In this study, crizotinib showed marked antitumor activity in patients with advanced ROS1-rearranged NSCLC. ROS1 rearrangement defines a second molecular subgroup of NSCLC for which crizotinib is highly active.’ ”