Fostamatinib: A Review of its Clinical Efficacy and Safety in the Management of Chronic Adult Immune Thrombocytopenia

Management of chronic immune thrombocytopenia (ITP) is going through a transition, with the main driving forces being a better understanding of the disease, recognition that platelet count is less important than bleeding symptoms, and the availability of new therapies. The heterogeneity of chronic ITP makes treatment challenging, and highlights the need for a personalized approach. A key aspect of tailored treatment is the availability of agents to target specific underlying pathophysiological mechanisms. In this review, we examine the evidence for orally bioavailable fostamatinib and its active moiety, tamatinib (R406), which has been approved for the treatment of chronic adult ITP. Fostamatinib inhibits FcR-triggered, Syk-dependent cytoskeletal rearrangement during phagocytosis and, as such, represents an active therapy targeting a previously unexplored mechanism of ITP pathogenesis.