A Study to Assess the Tolerability of Ianalumab (VAY736) With Investigator's Choice Thrombopoietin Receptor Agonist (IC TPO-RA) in Patients With Primary Immune Thrombocytopenia (ITP)

Key Inclusion Criteria: * Signed informed consent must be obtained prior to participation in the study. * Patients aged 18 years and older on the day of signing the informed consent. * ITP cohort only: Confirmed diagnosis of primary ITP that has previously responded to corticosteroid treatment or IVIG treatment but the response was not sustained (response is defined as a platelet count ≥ 50 G/L). * ITP cohort only: Received at least one prior treatment for ITP. * ITP cohort only: Patients with a platelet count \< 100 G/L who are receiving a TPO-RA. Patients may already be receiving a TPO-RA or may start a TPO-RA at the time of screening. All patients should be on a stable dose of TPO-RA for at least 14 days prior to first dose of ianalumab. Note: during the screening period, a documented assessment of platelets \< 100 G/L is mandatory for enrollment. For patients who received rescue medication before screening, platelet count results obtained prior to the start of the rescue therapy should be used to assess eligibility if collected within 14 days prior to screening. * ES cohort only: Patients with clinical diagnosis of primary ES with active thrombocytopenia (\< 100 G/L) with warm autoimmune hemolytic anemia (wAIHA) for whom a TPO-RA is appropriate per Investigator. * ES cohort only: Inadequate response to or relapse after treatment with corticosteroid therapy. * ES cohort only: Diagnosis confirmed by current or past positive direct antiglobulin test (DAT) (IgG+, with or wit…