Fostamatinib (R788) disodium hexahydrateis a prodrug of the active metabolite R406, which is a potent, ATP-competitive inhibitor of Syk kinase with Ki/IC50 of 30/41 nM.
Fostamatinib (R788) dose-dependently inhibits anti-IgE-mediated CHMC degranulation with an EC50 of 56 nM, inhibits all phosphorylation events downstream of Syk signaling.
Fostamatinib (R788) specifically inhibits FcγR signaling in human mast cells, macrophages, and neutrophils.
R788 can inhibit local inflammatory injury mediated by immune complexes; reduces immune complex-mediated inflammation in arthritis models.
