Fostamatinib

Fostamatinib (R788), a prodrug of the active metabolite R406, is a potent Syk inhibitor with IC50 of 41 nM.
Fostamatinib has been investigated for the treatment and basic science of Rheumatoid Arthritis and Immune Thrombocytopenic Purpura (ITP). It was approved on April 17, 2018 under the trade name Tavalisse for use in ITP. Fostamatinib has also been granted orphan drug status by the FDA.|Fostamatinib is an orally available small molecule inhibitor of spleen tyrosine kinase that is used to treat chronic immune thrombocytopenia. Fostamatinib is associated with transient and usually mild elevations in serum aminotransferase levels during therapy but has yet to be linked to instances of clinically apparent acute liver injury.|Fostamatinib is a small molecule Syk kinase inhibitor with potential anti-inflammatory and immunomodulating activities. Fostamatinib inhibits Syk kinase-mediated IgG Fc gamma receptor signaling, resulting in inhibition of the activation of mast cells, macrophages, and B-cells and related inflammatory responses and tissue damage. Syk kinase, widely expressed in hematopoietic cells, is a nonreceptor tyrosine kinase that is involved in coupling activated immunoreceptors to signal downstream events that mediate diverse cellular responses, including proliferation, differentiation, and phagocytosis.