Definition

A drug used to treat thrombocytopenia (a low blood platelet count) in adults with chronic immune thrombocytopenia (ITP) that did not get better with other treatment. ITP is a condition in which platelets are destroyed by the immune system. Fostamatinib disodium is also being studied in the treatment of other conditions and types of cancer. It blocks an enzyme called Syk, which may help keep the immune system from destroying platelets. Fostamatinib disodium is a type of tyrosine kinase inhibitor. Also called R788 sodium, Syk kinase inhibitor R-935788, and Tavalisse.