A small molecule inhibitor of the receptor tyrosine kinases (RTKs) anaplastic lymphoma kinase (ALK) and nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), with potential antineoplastic activity. Upon administration, TAE684 binds to and inhibits ALK and NPM-ALK tyrosine kinases, which leads to a disruption of ALK- and NPM-ALK mediated signaling and eventually inhibits tumor cell growth in ALK- and NPM-ALK overexpressing tumor cells. ALK belongs to the insulin receptor superfamily and plays an important role in nervous system development. ALK dysregulation and gene rearrangements are associated with a series of tumors. NPM-ALK is an oncogenic fusion protein associated with ALK-positive anaplastic large cell lymphoma. ALK mutations are also associated with acquired resistance to small molecule tyrosine kinase inhibitors.