Efficacy and Safety of Syk and BTK Inhibitors in Immune Thrombocytopenia: A Comprehensive Review of Emerging Evidence.

Abstract

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by a reduced platelet count, resulting in bleeding risks and compromised quality of life. Advances in understanding ITP pathogenesis have revealed critical roles for spleen tyrosine kinase (Syk) and Bruton's tyrosine kinase (BTK) in Fc receptor (FcR)-mediated immune pathways, which are central to autoantibody production and platelet destruction. We sought to evaluate the efficacy and safety of Syk and BTK inhibitors in the management of ITP. PubMed/Medline, Scopus, and Web of Science databases were systematically searched up to July 28, 2024. Clinical studies with available full-text in English were included. Fostamatinib, an FDA-approved Syk inhibitor, has shown efficacy in enhancing platelet counts and reducing bleeding events in refractory ITP patients. Among the newer Syk inhibitors, sovleplenib demonstrated rapid and sustained platelet increases in clinical trials, with an 80% response rate at the 300 mg dosage and a favorable safety profile. Additionally, BTK inhibitors, including rilzabrutinib and orelabrutinib, have shown potential in clinical trials, offering increased platelet stability and favorable safety profiles in ITP cases. Syk and BTK inhibitors hold potential as targeted therapies for refractory ITP, with evidence supporting their ability to improve clinical outcomes and enhance patient quality of life. Continued research is warranted to optimize these therapies and confirm their long-term efficacy and safety in diverse patient populations.