Discovery of novel tetracyclic compounds as anaplastic lymphoma kinase inhibitors.

Anaplastic lymphoma kinase (ALK) receptor tyrosine kinase is considered a promising therapeutic target for human cancers. We identified novel tetracyclic derivatives as potent ALK inhibitors. Among them, compound 27 showed strong cytotoxicity against KARPAS-299 with an IC(50) value of 21 nM and significant antitumor efficacy in ALK fusion-positive blood and solid cancer xenograft models in mice without body weight loss.