The recent first global approval of fostamatinib has been reviewed in detail in the First Global Approval report in Adis’ journal Drugs, based on the development milestones tracked in AdisInsight.
Fostamatinib (TAVALISSE™) received its first global approval in April 2018 in the US for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment. The agent, developed by Rigel Pharmaceuticals is a spleen tyrosine kinase (SYK) inhibitor. Fostamatinib is a prodrug that, after being administered orally, is converted in the gut to the active metabolite R 406. R 406 inhibits SYK, which is a key signalling component with a role in platelet destruction in patients with ITP.  
Fostamatinib was granted Orphan Drug status although it was approved by the FDA after standard review; the approval was supported by data from 163 patients enrolled in the FIT programme that included an initial proof-of-concept study, two phase three trials  and an open-label extension.
James Bussel, M.D., professor emeritus of pediatrics at Weill Cornell Medicine and the principal study investigator on the FIT Phase 3 program explained that “Chronic ITP is challenging to treat because the heterogeneity of the disease makes it difficult to predict how an individual patient will respond to available treatments and not all patients can find a treatment that works well for them,… The FDA approval of fostamatinib arms physicians with a new treatment option, which works via a novel mechanism,” he continued. 
Fostamatinib is also under late stage clinical development in Canada and the EU for ITP. The agent is also under development for acute haemolytic anaemia, IgA nephropathy, chronic graft versus host disease and ovarian cancer in various countries globally. 
The prescribing information for fostamatinib warns of hypertention, hepatotoxicity, diarrhoea, neutropenia and embryo-fetal toxicity with use of the product.
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