Xalkori ZAL-kor-ee) is a drug used to treat non-small cell lung cancer that has spread to other parts of the body. It is used in patients whose cancer is anaplastic lymphoma kinase (ALK) positive or ROS1 positive. It is also being studied in the treatment of other types of cancer. Xalkori blocks the proteins made by the ALK and ROS1 genes. Blocking these proteins may stop the growth and spread of cancer cells. Xalkori may also prevent the growth of new blood vessels that tumors need to grow. It is a type of tyrosine kinase inhibitor and a type of antiangiogenesis agent. Also called crizotinib.