Immune thrombocytopenia: contemporary pathophysiology, treatment gaps, and the role of novel mechanisms in patient-centered care.

Immune thrombocytopenia (ITP) is a chronic autoimmune disorder associated with platelet destruction and increased bleeding risk, substantial economic burden, and impairment of health-related quality of life. The pathophysiology of ITP involves increased platelet destruction and impaired platelet production due to a multifactorial breakdown of immune tolerance driven by dysregulated B and T cells. Advances in understanding ITP pathophysiology have led to the development of new immune-modulating therapies, such as Bruton tyrosine kinase (BTK) inhibitors. Rilzabrutinib (Wayrilz; Sanofi) is an oral BTK inhibitor recently approved for treatment of adult patients with persistent or chronic ITP who have had an insufficient response to a previous treatment. Rilzabrutinib targets several aspects of ITP disease pathophysiology by modulating multiple immune pathways. Approval was based on results from a phase 3 trial (LUNA 3 [NCT04562766]), in which patients with ITP who received rilzabrutinib demonstrated a rapid, durable platelet response and improvements in fatigue and bleeding with a tolerable safety profile.