Emerging Agents Reshaping the ITP Landscape

EP: 1.Understanding Immune Thrombocytopenia: Pathophysiology, Classification, and Differentiation

EP: 2.Diagnostic and Patient Education Strategies in ITP

EP: 3.Managing Bleeding Risk in Patients with ITP

EP: 4.Living with ITP: Impact of Fatigue and Other Symptoms on Patients’ Quality of Life

EP: 5.Tailoring Care in ITP Through a Health Equity Lens

EP: 6.Looking Ahead in ITP: Addressing Unmet Needs and Embracing Innovation

EP: 7.Key Clinical Signs and Symptoms Used in Diagnosis of Immune Thrombocytopenia

EP: 8.Clinical Decision-Making in ITP: Timing Treatment Initiation and Therapy Goals

EP: 9.Current Treatment Algorithm for Management of Immune Thrombocytopenia

EP: 10.Addressing the Limitations of Current ITP Therapies

EP: 11.Risks versus Benefits: ITP Treatment Side Effects and the Influence on Patients’ Quality of Life

EP: 12.Defining Treatment Success, Failure, and When to Reassess Patients’ Management of ITP

EP: 13.Navigating Refractory ITP: Clinical Insights and Treatment Strategies

EP: 14.Potential Impact of Emerging Therapies on Patients Living with ITP

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EP: 15.Emerging Agents Reshaping the ITP Landscape

EP: 16.Understanding Gaps and Limitations in Current ITP Therapies

The FDA's August 2024 approval of rilzabrutinib, a Bruton tyrosine kinase (BTK) inhibitor, represents a paradigm shift for individuals with ITP following insufficient response to previous treatments. This novel therapeutic approach addresses multiple unmet needs by targeting the fundamental autoimmune mechanisms driving ITP rather than simply managing symptoms or stimulating platelet production through traditional pathways.

ITP pathophysiology involves complex immune dysregulation where patients develop elevated pro-inflammatory cytokines (interleukin-2, interferon-gamma, interleukin-17) alongside reduced regulatory cytokines (interleukin-10, TGF-beta). This imbalance triggers autoantibody production, specifically IgG antibodies that target platelet surface glycoproteins like GP2B3A and GP1B9, leading to platelet destruction in the spleen through Fc-gamma receptor-mediated phagocytosis. These autoantibodies also impair platelet production by inhibiting megakaryocyte maturation and platelet formation in bone marrow. B cell dysregulation further amplifies this autoantibody overproduction, creating a self-perpetuating inflammatory cycle.

BTK inhibition offers mechanistic advantages by targeting this intracellular protein expressed in B cells, macrophages, and platelets. By disrupting BTK signaling, rilzabrutinib modulates the dysregulated immune response and reduces pro-inflammatory cytokine production, including the NLRP3 inflammasome. This multi-targeted immunomodulation represents a fundamental departure from existing therapies, potentially addressing not only platelet destruction but also the systemic inflammation believed to contribute to quality of life impairments, particularly the debilitating fatigue experienced by individuals living with ITP.