Anaplastic lymphoma kinase (ALK), a member of the insulin receptor superfamily of receptor tyrosine kinases, has been implicated in oncogenesis in hematopoietic and non-hematopoietic tumors. The aberrant expression of full-length ALK receptor proteins has been reported in neuroblastomas and glioblastomas; and ALK fusion proteins have occurred in anaplastic large cell lymphoma. The study of ALK fusion proteins has also raised the possibility of new therapeutic treatments for patients with ALK-positive malignancies. (Pulford et al., Cell. Mol. Life. Sci. 61:2939-2953 (2004)).
Focal Adhesion Kinase (FAK) is a key enzyme in the integrin-mediated outside-in signal cascade (D. Schlaepfer et al., Prog Biophys Mol Biol 1999, 71, 43578). The trigger in the signal transduction cascade is the autophosphorylation of Y397. Phosphorylated Y397 is a SH2 docking site for Src family tyrosine kinases; the bound c-Src kinase phosphorylates other tyrosine residues in FAK. Among them, phosphorylated Y925 becomes a binding site for the SH2 site of Grb2 small adaptor protein. This direct binding of Grb2 to FAK is one of the key steps for the activation of down stream targets such as the Ras-ERK2/MAP kinase cascade.
Zeta-chain-associated protein kinase 70 (ZAP-70), a member of the protein tyrosine kinase family, is of potential prognostic importance in chronic lymphocytic leukemia (CLL). ZAP-70, known to be of importance in T and NK cell signaling but absent in normal peripheral B cells, is expressed in the majority of the poorer prognosis unmutated CLL and absent in most cases with mutated IgVH genes. ZAP-70 is also expressed in a minority of other B cell tumors. (Orchard et al., Leuk. Lymphoma 46:1689-98 (2005)).
Insulin-like growth factor (IGF-1) signaling is highly implicated in cancer, with the IGF-1 receptor (IGF-1R) as the predominating factor. IGR-1R is important for tumor transformation and survival of malignant cells, but is only partially involved in normal cell growth. Targeting of IGF-1R has been suggested to be a promising option for cancer therapy. (Larsson et al., Br. J. Cancer 92:2097-2101 (2005)).
Because of the emerging disease-related roles of ALK, FAK, ZAP-70 and IGF-1R, there is a continuing need for compounds which may be useful for treating and preventing a disease which responds to inhibition of ALK, FAK, ZAP-70 and/or IGF-1R.