| Abstract: | Introduction: The critical role of the activity of the nucleophosmin- anaplastic lymphoma kinase (NPM-ALK) fusion protein in anaplastic large-cell lymphoma prompted drug discovery programs directed against ALK. Drug discovery efforts increased after finding that about 4% of non-small-cell lung cancers (NSCLCs) possess an EML4-ALK fusion protein. Areas covered: The author provides a review of the development of crizotinib, an orally effective c-Met and ALK protein kinase inhibitor. The article highlights its beginning with the X-ray crystallographic structure of a lead compound (PHA-0665752) bound to the active site of the kinase domain of c-Met. Expert opinion: Studies of patients with EML4-ALK–positive NSCLC showed that crizotinib was clinically effective and led to its approval in August 2011. The use of lipophilic efficiency played a crucial role in the development of crizotinib from a lead c-Met inhibitor. The use of X-ray crystal structures from lead compounds, bound to their targets, is increasing in the drug discovery process owing to its effectiveness. That the drug also inhibits ALK and ALK-fusion proteins was serendipitous, however. The discovery of the EML4-ALK fusion protein in some NSCLC patients has led to the testing and rapid approval of the compound. |
