FLT3 (including D835/ITD mutants), also PDGFR-alpha/beta

Class

Small molecule type I pan-FLT3/PDGFR kinase inhibitor

Pathway

FLT3 and PDGFR signal transduction

FLT3 is a receptor tyrosine kinase expressed on early blood-forming (hematopoietic) cells, where it normally transmits growth signals that support the development of white blood cells. In acute myeloid leukemia, FLT3 frequently acquires activating mutations—either internal tandem duplications (ITD) or point mutations in the kinase domain such as D835—that lock the receptor into a continuously active state, driving uncontrolled proliferation of leukemic cells. Small molecule kinase inhibitors targeting FLT3 aim to block this aberrant signaling and slow disease progression. This particular compound class is a pan-FLT3 inhibitor, meaning it is designed to suppress both the wild-type receptor and the various mutant forms, including the harder-to-target D835 point mutants that can escape some other inhibitors. It additionally inhibits PDGFR-alpha and PDGFR-beta, related receptor tyrosine kinases that share structural similarity with FLT3; this cross-reactivity is a consequence of kinase family homology rather than a separate design goal, though PDGFR signaling is itself relevant in certain proliferative and fibrotic conditions. Broadly, FLT3-directed kinase inhibition matters wherever constitutive FLT3 activation is a disease driver, most notably in FLT3-mutated acute myeloid leukemia, where resistance to earlier-generation inhibitors—often through emergence of D835 mutations—creates an ongoing need for inhibitors with broader mutant coverage.