A Phase 3, Randomized, Multicenter, Open-label Study to Evaluate the Efficacy and Safety of Romiplostim Plus Predniso(lo)ne vs. Predniso(lo)ne Alone for the Treatment of Adults With Previously Untreated Primary Immune Thrombocytopenia (ITP).

Inclusion Criteria: * Age ≥18 years or adult legal age within country if older than 18 years. * Diagnosis of primary ITP according to the 2019 International Consensus (ICR) that is previously untreated and requires treatment. * Note: The investigator should ensure that the diagnosis of primary ITP is established by excluding other causes of isolated thrombocytopenia, as outlined in the 2019 ICR, which states that the diagnosis of primary ITP is principally based on the exclusion of other causes of isolated thrombocytopenia. * Note: If emergency treatment is necessary, platelet count perf…