A Clinical Study to Evaluate the Efficacy and Safety of LIV-GAMMA SN Inj.10% in Primary Immune Thrombocytopenia (ITP)

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