Abstract: The present invention concerns a method of treating idiopathic thrombocytopenia purpura (ITP) in a patient having ITP, which comprises: (a) administering romiplostim weekly to the patient; (b) increasing the weekly dose until a platelet count of at least about 50 to 200×109/L is reached; (c) decreasing the weekly dose of romiplostim if the platelet count remains ?200×109/L for two consecutive weeks; (d) discontinuing romiplostim if the platelet count has remained ?200×109/L for two consecutive weeks when the weekly dose is 1 ?g/kg or the platelet count is ?400×109/L; and (e) if a platelet count ?200×109/L is reached within the first 4 to 12 weeks of treatment, maintaining a treatment-free period of at least about 24 weeks during which the patient receives no romiplostim.