The purpose of this study is to evaluate the efficacy and safety of LIV-GAMMA SN Inj.10% administered for 2 days in adult subjects with primary immune thrombocytopenia (ITP). The primary objective of this study is to determine the responder rate. A response is defined as a platelet count of ≥30×10^9/L and at least a 2-fold increase of the baseline, confirmed on at least 2 separate occasions at least 7 days apart without bleeding. The secondary objectives are to evaluate the further efficacy assessments including time to response and duration of response, and the safety of LIV-GAMMA SN Inj.10%.

Inclusion Criteria:

• Completed informed consent process
• Male or female aged ≥19 years
• Diagnosis of chronic ITP (≥12 months since diagnosis)
• Mean screening platelet count of <30×10^9/L from 3 qualifying platelet counts performed within 14 days before the start of treatment, with no individual platelet count above 35×10^9/L
• No other factors inducing ITP
• If the patient is taking corticosteroid, attenuated androgen, cyclophosphamide, azathioprine or other drugs for ITP, the treatment regimen and dose should be stable at least 1 month prior to screening and should be lasted during this study
• Females of child-bearing potential with a negative urine pregnancy test and who agree with contraception during this study

Exclusion Criteria:

• Patients who have allergy or hypersensitivity to blood products, blood-derived products, intravenous immunoglobulin (IVIg) or immunoglobulin G (IgG)
• Patients who have immunoglobulin A (IgA) deficiency
• Patients who were immunized with live attenuated vaccines within 12 months from the first administration of LIV-GAMMA SN Inj.10%
• Patients who had received IVIg or blood/blood-derived products within 1 month from the first administration of LIV-GAMMA SN Inj.10%
• Patients who had received other investigational products within 1 month from the first administration of LIV-GAMMA SN Inj.10%
• Patients who had received Rituximab within 3 months from the first administration of LIV-GAMMA SN Inj.10%
• Patients who were taking anticoagulants or other agents related to platelet function (e.g., Aspirin, other NSAID) at the time of screening
• Patients who are pregnant and nursing
• Patients who are positive for human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) at the time of screening
• Patients who have 3-fold higher levels of alanine transaminase (ALT), aspartate transaminase (AST) than the upper limit of normal at the time of screening
• Patients who suffered from severe renal impairment (eGFR<30 mL/min/1.73 m^2 at the time of screening)
• Patients who had history of deep vein thrombosis (DVT) or thrombotic complications against IVIg therapy
• Patients who had history of neurovascular or cardiovascular disorders (e.g., Blood hyperviscosity, transient ischemic attack (TIA), stroke, other thromboembolism, unstable angina)
• Patients who have an ongoing history of acute or chronic condition that affect to the participation of this study
• Patients who have an ongoing history of medical condition inducing secondary immune deficiency (e.g., Leukemia, lymphoma, multiple myeloma, HIV infection, chronic or cyclic neutropenia (absolute neutrophil count<500/mm^3)
• Patients who are suffering from hypertension (systolic blood pressure>160 mmHg or diastolic blood pressure>100 mmHg)
• Patients who have hemoglobin level≤10 g/dL at the time of screening