Study of Ianalumab Versus Placebo in Addition to First-line Corticosteroids in Primary Immune Thrombocytopenia (ITP)

Inclusion Criteria: * Signed informed consent prior to participation in the study. * Male or female participants aged 18 years and older on the day of signing informed consent * Primary ITP diagnosed within 3 months before initiating first-line ITP therapy (corticosteroids, IVIG) * Platelet count below 30 G/L before starting any first-line ITP therapy (corticosteroids, IVIG) * Response (platelet count \>=50 G/L) to corticosteroids (+/- IVIG) at any time prior to randomization. Note: Platelet count measured within 7 days of platelet transfusion will not be considered as response. Key Exclusion Criteria: * Evans syndrome or any other cytopenia (patients with low grade anemia related to bleeding or iron deficiency are eligible) * Current life-threatening bleeding * Previous ITP treatment, including splenectomy, except for corticosteroids and/or IVIG initiated as first-line therapy for up to 28 days before randomization and rescue corticosteroids and/or IVIG given prior to confirmed diagnosis of primary ITP . * Prior use of B-cell depleting therapy (e.g., rituximab). * Absolute neutrophil count below 1.0 G/L at randomization * Participants with concurrent coagulation disorders and/or receiving anti-platelet or anticoagulant medication with an exemption of low dose of acetylsalicylic acid Other protocol-defined Inclusion/Exclusion may apply.