Definition

An orally bioavailable selective inhibitor of fusion products and mutated forms of the proto-oncogene receptor tyrosine kinase rearranged during transfection (RET), with potential antineoplastic activity. Upon oral administration, the RET inhibitor KL590586 selectively binds to and inhibits the activity of RET fusions and mutations. This results in an inhibition of cell growth of susceptible tumors cells that exhibit increased RET activity. RET overexpression, activating mutations, and fusions result in the upregulation and/or overactivation of RET tyrosine kinase activity in various cancer cell types; dysregulation of RET activity plays a key role in the development and progression of these cancers.