VAYHIT3: An Open-Label, Single-Arm, Phase II Trial to Evaluate the Efficacy and Safety of Ianalumab in Patients with Primary Immune Thrombocytopenia (ITP) Previously Treated with at Least 1 Corticosteroid and 1 Thrombopoietin Receptor Agonist (TPO-RA)

Background: In patients with ITP, autoreactive B cells mediate the production of autoantibodies that target platelets and megakaryocytes, resulting in an increased rate of platelet destruction and decreased platelet production. B-cell activating factor (BAFF) regulates the differentiation, proliferation and survival of B cells via interactions with the BAFF receptor (BAFF-R). Patients with ITP have elevated serum BAFF levels, which positively correlate with increased disease activity. Ianalumab is a novel, fully human immunoglobulin G1 monoclonal antibody that targets BAFF-R and has a unique dual mechanism of action: direct B-cell depletion mediated by antibody-dependent cellular cytotoxicity and inhibition of B-cell differentiation, proliferation and survival via blockade of BAFF-R-mediated signaling.