Fostamatinib, sold under the brand names Tavalisse and Tavlesse, is a tyrosine kinase inhibitor medication for the treatment of chronic immune thrombocytopenia (ITP). The drug is administered by mouth.Fostamatinib blocks the activity of the enzyme spleen tyrosine kinase (SYK). This enzyme is involved in stimulating parts of the immune system. By blocking SYKs activity, fostamatinib reduces the immune systems destruction of platelets, so allowing the platelet count to rise, which reduces the likelihood of excessive bleeding.The most commonly reported side effects are diarrhea, high blood pressure, nausea, respiratory infection, dizziness, increased liver enzymes, rash, abdominal pain, fatigue, chest pain and decreased white blood cell count.The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication. Medical uses
Fostamatinib is a drug used to treat adults with low platelet count due to chronic immune thrombocytopenia (ITP) when a prior treatment for ITP has not worked well enough. Chronic immune thrombocytopenia is an autoimmune bleeding disorder where the blood doesnt clot as it should because of a low platelet count. Pharmacology
Mechanism of action
The tablets are formulated as fostamatinib disodium hexahydrate, a disodium hexahydrate 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. Syk is a protein tyrosine kinase associated with various inflammatory cells, including macrophages, which are presumed to be the cells responsible for ITP platelet clearance.
This study is a Phase 2, multi-center, open label, Simon two-stage study to evaluate the safety and efficacy of fostamatinib disodium in the treatment of warm antibody autoimmune hemolytic anemia. Primary outcome measures examined include a hemoglobin response measured by levels higher than 10 g/dL and 2 g/dL higher than the baseline hemoglobin. Responses were studied for a period of 12 weeks and for a dose of 150 mg in the morning and evening. The study began in April 2016 and is estimated to conclude in September 2017. The study is currently recruiting participants from U.S. states including Arizona, California, D.C., Massachusetts, New York, North Carolina, and Texas. Subjects must have had a diagnosis of primary or secondary warm antibody AIHA, and must have failed at least 1 prior treatment regimen for AIHA. Subjects cannot have a platelet count less than 30,000/μL, have AIHA secondary to autoimmune disease, have uncontrolled or poorly controlled hypertension, or have cold antibody AIHA, cold agglutinin syndrome, mixed type AIHA, or paroxysmal cold hemoglobinuria. Immunoglobulin A nephropathy
Fostamatinib as a treatment for IgA nephropathy (IgAN) is in Phase II trials, which will conclude at the end of 2016. IgAN is a chronic autoimmune disease associated with inflammation in the kidneys that reduces their ability to successfully filter blood. There are currently no disease-targeted therapies for IgAN. Participants are currently being recruited from the US, Austria, Germany, Hong Kong, Taiwan, and the UK.