A Randomized Study to Assess the Safety of GRF6019 Infusions in Subjects With Mild to Moderate Alzheimer's Disease

Inclusion Criteria: * Diagnosis of probable AD based upon the National Institute on Aging-Alzheimer's Association (NIA-AA) Criteria * MMSE Score 12-24 inclusive * Modified Hachinski Ischemia Scale (MHIS) score of ≤ 4 * Provided a signed and dated informed consent form (either the subject and/or subject's legal representative as well as the trial partner) Exclusion Criteria: * Evidence of clinically relevant neurological disorder(s) other than probable AD * History of blood coagulation disorders or hypercoagulability; any concurrent use of an anticoagulant therapy. (e.g., heparin, warfarin, thrombin inhibitors, Factor Xa inhibitors). Use of antiplatelet drugs (e.g., aspirin or clopidogrel) is acceptable. * Initiation or change in the dosage of cholinesterase inhibitors (AChEI), memantine, Axona, vitamin E supplementation or selegiline within 3 months prior to screening. * Heart disease (or history thereof), as evidenced by myocardial infarction, unstable, new onset or severe angina, or congestive heart failure (New York Association Class II, III or IV) in the 6 months prior to dosing; uncontrolled high blood pressure (systolic blood pressure of 160 mmHg or higher and/or diastolic blood * Prior hypersensitivity reaction to any human blood product or intravenous infusion; any known clinically significant drug allergy. * Treatment with any human blood product, including transfusions and intravenous immunoglobulin, during the 6 months prior to screening. * History of immunoglobulin A (IgA), haptoglobulin or C1 inhibitor deficiency; stroke, anaphylaxis, or thromboembolic complications of intravenous immunoglobulins. * Hemoglobin \<10 g/dL in women; and \<11 g/dL in men.