Inclusion Criteria:

• Age >= 18 and <= 65 years
• ITP diagnosed at least 6 months prior to study entry by history, physical exam, blood count and blood smear
• Baseline platelet count of <= 20 x 10 to the 9th/L determined prior to administration of the study drug on the day of the first infusion
• No IVIG treatment for ITP during the two weeks prior to the first infusion of the study drug
• For females of child bearing potential, use of adequate birth control measures during study participation
• Written informed consent

Exclusion Criteria:

• Serum values of ALT, AST, alkaline phosphatase, and total bilirubin exceeding 2.5 times the upper limit of normal at screening
• Renal dysfunction defined as serum creatinine greater than or equal to 2 mg/dL at screening
• Underlying other autoimmune or lymphoproliferative disorder
• Uncontrolled hypertension
• Cardiac insufficiency NYHA III and IV, coronary heart disease (CHD) NYHA III and IV
• Malignancy or history of malignancy
• Documented selective IgA deficiency (<= 10 mg/dL)
• Treatment with another investigational drug in the four weeks prior to study entry or current treatment with another investigational product
• History of severe adverse reactions to blood and/or blood products
• Pregnancy or lactation
• Positivity for HIV, or HCV antibodies, or HBsAg
• History of unresponsiveness to IVIG defined as a peak increment in platelet count <= 20,000/µL coincident with the last IVIG treatment course prior to study entry