Of the 43 patients with an overall platelet response, 4 patients were on a concomitant medication, including 3 on steroids (for 62 days, 67 days and 14 years prior to first dose of fostamatinib) and 1 on azathioprine (for 197 days prior to the first dose of fostamatinib)

Of the 43 patients with an overall platelet response, 4 patients were on a concomitant medication, including 3 on steroids (for 62 days, 67 days and 14 years prior to first dose of fostamatinib) and 1 on azathioprine (for 197 days prior to the first dose of fostamatinib). in 43% of patients on fostamatinib vs. 14% on placebo (P= .0006). Median time to response was 15 days (on 100 mg bid), and 83% responded within 8 weeks. The most common adverse events were diarrhea (31% on fostamatinib vs. 15% on placebo), hypertension (28% vs. 13%), nausea (19% vs. 8%), dizziness (11% vs. 8%), and ALT increase (11% vs. 0%). Most events were mild or moderate and resolved spontaneously or with medical management (antihypertensive, antimotility agents). Fostamatinib produced clinicallymeaningful responses in ITP patients including those who failed splenectomy, thrombopoietic agents, and/or rituximab. Fostamatinib is a novel ITP treatment option that targets an important mechanism of ITP pathogenesis. == 1. INTRODUCTION == Immune thrombocytopenia (ITP) is an autoantibodymediated bleeding disorder, characterized primarily by accelerated platelet destruction and also by impairment of megakaryocyte function.1,2The constellation of symptoms varies between Tubeimoside I patients and can include severe thrombocytopenia, with bleeding ranging from none to skin and mucosal bleeding, to intracranial, gastrointestinal, and genitourinary bleeding.2,3,4Mortality rates are very low but increase with age, certain comorbidities, and longterm severe disease.3,5Quality of life is often impaired in areas of physical functioning and mental health.6,7,8 Patients needing treatment usually receive Tubeimoside I steroids with or without intravenous immunoglobulin (IVIG) as firstline therapy, but the great majority of patients require additional treatment due to intolerability or relapse. Current guidelines for secondline and subsequent therapies are broad and nonprescriptive. There are many therapies available, but no comparative, randomized, controlled studies exist to facilitate treatment choice.9,10Splenectomy is the only potentially curative approach, which is effective in a majority of patients initially, but some patients subsequently relapse. This surgical option is declining in Tubeimoside I use due to the availability of noninvasive options.11Medical therapies, such as rituximab, thrombopoietin receptor agonists, and immunosuppressive agents, have been effective in many patients and are chosen according to physician and patient preference. Some patients do not respond, or respond but relapse, when treated with second line treatments and develop persistent and then chronic disease. Those who do not improve often cycle endlessly through the various treatment options. Despite the multiple agents available, there is an unmet medical need for patients with ITP.6,7,12,13 Fostamatinib, an orally bioavailable, small molecule spleen tyrosine kinase (Syk) inhibitor, was approved in April 2018 by the US Food and Drug Administration (FDA) for the treatment of chronic ITP in adults who have had an insufficient response to a prior therapy. All activating Fc receptors signal via Syk, which has roles in cellular proliferation, differentiation, survival, immune regulation, and cytoskeletal rearrangements during phagocytosis.14,15,16Syk is also linked to signaling of the B cell receptor and has been implicated in autoantibody production.17Inhibition of Syk using fostamatinib reduced platelet destruction in a mouse model of passive ITP, underscoring the role of Syk in phagocytosis of antibodycoated platelets.18Clinical results with fostamatinib were first reported SFN in patients with chronic ITP in a single center study in 2009 2009. Of 16 patients, 8 (50%) achieved longterm responses, with manageable adverse events (AEs).18Fostamatinib was also extensively studied in rheumatoid arthritis, demonstrating efficacy and establishing a safety profile in a total of more than 3000 patients.19,20,21,22,23,24,25This report describes two identical, parallel, multicenter, randomized, doubleblind, placebocontrolled, phase 3 studies comparing fostamatinib to placebo in 150 adults with persistent and primarily chronic ITP of very longlasting duration, who had failed a number of prior treatments. == 2. METHODS == == 2.1. Study design == FIT1 (NCT02076399) and Suit2 (NCT02076412) had been identicallydesigned, parallel, stage 3, multicenter, randomized, doubleblind, placebocontrolled studies of fostamatinib in comparison to placebo for the treating persistent/persistent ITP. From July 2014 to Apr 2016 at 35 centers in THE UNITED STATES Suit1 sufferers enrolled, Australia, and European countries; FIT2 sufferers.