Crizotinib is a tyrosine kinase receptor inhibitor. More specifically, it inhibits anaplastic lymphoma kinase (ALK), hepatocyte growth factor receptor (HGFR, c-MET), and Recepteur d'Origine Nantais (RON). Abnormalities in the ALK gene caused by mutations or translocations may lead to expression of oncogenic fusion proteins. In patients with NSCLC, they have the EML4-ALK gene. Crizotinib inhibits ALK tyrosine kinase which ultimately results in decreased proliferation of cells that carry the genetic mutation and tumour survivability.
Crizotinib is metabolized by CYP3A4 and CYP3A5 in which these enzymes mediates the O-dealkylation of the drug.