This study is evaluating the safety, tolerability, and feasibility of GRF6019, a plasma-derived product, administered as an intravenous (IV) infusion, to subjects with mild to moderate Alzheimer's disease.

This is a randomized, double-blind, dose-comparison concurrent control study to assess the safety, tolerability, and feasibility of GRF6019, a plasma-derived product, administered by intravenous (IV) infusion to subjects with mild to moderate Alzheimer's disease.

Subjects will be randomized 1:1 to a low dose or a high dose of active treatment in a double-blind manner. All subjects will receive one infusion per day at the randomized dose for 5 consecutive days during Week 1 and, again, during Week 13 (for a total of 10 doses per subject). All IV infusions will take place at an inpatient research unit while the follow-up visits after each treatment period will be on an outpatient basis. Subjects will participate for a total of 6 months in this study.

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.