GSK1838705A

GSK1838705A is a potent inhibitor of IGF-IR, IR and ALK with IC50 of 2.0 nM, 1.6 nM and 0.5 nM, respectively. The insulin-like growth factor-I receptor (IGF-IR) signaling pathway is activated in various tumors, and inhibition of IGF-IR kinase provides a therapeutic opportunity in these patients. GSK1838705A blocks the in vitro proliferation of cell lines derived from solid and hematologic malignancies, including multiple myeloma and Ewing's sarcoma, and retards the growth of human tumor xenografts in vivo. GSK1838705A also inhibits the anaplastic lymphoma kinase (ALK), which drives the aberrant growth of anaplastic large-cell lymphomas, some neuroblastomas, and a subset of non-small cell lung cancers. The Anaplastic Lymphoma Kinase (ALK) is a receptor tyrosine kinase first identified as the product of a gene rearrangement in Anaplastic Large Cell Lymphoma. GSK1838705A inhibits ALK, with an IC(50) of 0.5 nmol/L, and causes complete regression of ALK-dependent tumors in vivo at well-tolerated doses. GSK1838705A is therefore a promising antitumor agent for therapeutic use in human cancers. GSK1838705A (60 mg/kg) inhibits the growth of established Karpas-299 xenografts with 93% tumor growth inhibition, with no effect on weights of the rats.