Alectinib(cas:1256580-46-7) is a potent and selective ALK inhibitor with IC50 of 1.9 nM.The possibility of targeting ALK in human cancer was advanced with the launch of crizotinib for NSCLC in the U.S. in 2011. The development of resistance to crizotinib in tumors, however, has led to the need for second-generation ALK inhibitors. One of these, alectinib hydrochloride, has been found to be an orally active, potent and highly selective ALK inhibitor with activity in ALK-driven tumor models. Alectinib has shown preclinical activity against cancers with ALK gene alterations, including NSCLC cells expressing the EML4-ALK fusion and ALCL cells expressing the NPM-ALK fusion. Alectinib was well tolerated and active in a phase I/II study conducted in Japan in patients with ALK-rearranged advanced NSCLC and in patients with ALK-positive NSCLC who had progressed on crizotinib.