PRN694 is a small molecule, covalent inhibitor somewhat selective for the TEC family kinases, IL-2-inducible T cell kinase (ITK) and TXK tyrosine kinase (also known as resting lymphocyte kinase or RLK) [2-3
]. In vitro
PRN694 is a potent inhibitor of Th1 and Th17 differentiation and cytokine production (IFN-γ production for Th1 and IL-17A for Th17), and in vivo
PRN694 markedly reduces disease progression in a mouse colitis model [2
]. It is suggested that dual ITK and RLK inhibition may represent a novel therapeutic model for amelioration of Th1-mediated inflammatory diseases.
Mechanistically PRN694 inhibits kinase activity by binding irreversibly to cysteine residue 442 of ITK and 350 of RLK [3
]. A series of compounds including PRN694 is claimed in patent WO2014036016 [1
]. Example 29 is an enantiomer of PRN694 with one unspecified stereocenter.