Fostamatinib is a spleen tyrosine kinase (Syk) inhibitor prodrug. Fostamatinib is administered orally in disodium salt preparations (e.g
. PubChem CID 25008120
and fostamatinib disodium hexahydrate CID 24828759
). It is rapidly converted to tamatinib
by alkaline phosphatases in intestinal enterocytes [6
]. Although development in rheumatoid arthritis was discontinued in 2013 due to a lack of observed efficacy, development continued in patients with chronic and persistent immune thrombocytopenia (ITP).