A Study of Ianalumab (VAY736) in Patients With Primary Immune Thrombocytopenia (ITP) Previously Treated With at Least Two Lines of Therapies

Inclusion Criteria: * Signed informed consent obtained prior to participation in the study. * Male or female participants aged 18 years and older on the day of signing informed consent. * Confirmed diagnosis of primary ITP. * Prior treatment with at least a corticosteroid (±IVIG) and a TPO-RA: * Prior additional therapies are allowed; the corticosteroid or the TPO-RA do not need to be the last treatment. * Prior response to IVIG/anti-D or a corticosteroid (platelet count ≥50 G/L) that was not maintained. * At last ITP treatment, loss of response, insufficient response, no response or intolerance. * Platelet count \<30 G/L and assessed as needing treatment (per physician's discretion) at screening. If concomitant ITP medication is clinically indicated, the platelet assessment showing a value \<30 G/L must be performed after at least 14 days on a stable dose of a corticosteroid or/and a TPO-RA (less than 10% variation from current dose) and continue stable thereafter. Key exclusion criteria: * Diagnosis of secondary thrombocytopenia. * Platelet or whole blood transfusion, plasmapheresis, or use of any other rescue medications within 14 days before first ianalumab infusion. * Participants with the following conditions at screening: * Neutrophils \<1000/mm3. * Immunoglobulin G (IgG) \<5 g/L * Treatment with a B-cell depleting therapy (e.g., rituximab) or anti-B-cell Activating Factor of the TNF Family (BAFF) (e.g., belimumab) within 12 weeks prior to the first administration of ianalumab. * Immunosuppressant drugs other than corticosteroids within 5 times the elimination half-life of the drug or 14 days before first ianalumab infusion, whichever is longer. * Prior splenectomy. Other protocol-defined inclusion/exclusion criteria may apply.