Andalusian Experience in the Use of Fostamatinib in Patients With ITP. FOSTASUR Study

Fostamatinib is a splenic tyrosine kinase (SYK) inhibitor whose indications include the treatment of chronic primary immune thrombocytopenia (PTI) refractory to first-line treatments. Data from two phase 3 studies in PTI, together with supporting safety data from a comprehensive program in 3,437 subjects with rheumatoid arthritis, led to the approval and registration of fostamatinib by health authorities in the US and in Europe.

Given the recent commercialization of fostamatinib for PTI, there is little data in real clinical practice that helps its general management: how to perform tapering, response rates in less refractory patients, experience in subjects with associated immunosuppressive therapies or thrombopoietin analogues, etc. These studies outside the clinical trial environment are relevant to plan needs, consumption, efficacy, and safety results in real clinical practice in our environment, the Andalusian region. The pivotal studies present experience on 102 cases and the real-life experience is of case series of less than 5 patients, with the population of patients treated in the Andalusian region as of December 31st being greater than 40 cases. For all these reasons the Andalusian Group of Congenital Coagulopathies proposes collecting what the experience has been like in their environment. Participation in this study is not intended to change the routine treatment patients receive as determined by their prescribing physicians. No clinic visits, procedures, evaluations, or tests will be required for the purposes of the study. This is multicenter retrospective data that will be collected from information generated during routine examinations and treatments performed by the investigator according to the standard of care.

Inclusion criteria

• Patients aged 18 years or older.
• Patients with ITP criteria according to clinical practice guidelines.

Exclusion criteria

• Patients with any medical or psychological condition that prevents them from following the procedures of normal clinical practice as determined by the investigator.
• Subjects with other concomitant hemostatic defects.
• Documented history or clinical evidence of medical conditions (other than ITP) that consider the underlying cause of thrombocytopenia.
• Diagnosis of secondary immune thrombocytopenia.
• Subject has a known allergy to fostamatinib or any of the ingredients included in its formulation.