What is "fostamatinib"

Fostamatinib is an experimental drug candidate for the treatment of a variety of diseases, originally developed by Rigel Pharmaceuticals. The drug is administered orally as a disodium salt, and is a prodrug of the active compound tamatinib (R-406), which is an inhibitor of the enzyme spleen tyrosine kinase (Syk), hence it is an syk inhibitor.