First in Human Study for Safety and Tolerability of AL003.

Inclusion Criteria

• •1. Total body weight between 50 and 120 kg, inclusive
• •2. Clinical laboratory evaluations (including chemistry panel fasted \[at least 8 hours\], complete blood count (CBC), and urine analysis) within the reference range for the test laboratory, unless deemed not clinically significant by the Investigator. A count of the segmented neutrophils and bands should be performed when results from the white blood cells (WBCs) are not within the reference range.
• •3. Negative test for selected drugs of abuse at screening (dose not include alcohol) and at admission (does include alcohol breath test). A positive result may be verified by re-testing (up to one false positive result permitted) and may be followed up at the discretion of the Investigator.
• •4. Females must be non-pregnant and non-lactating, and either surgically sterile, using double barrier method or abstinence.
• •5. In good health, determined by no clinically significant findings from medical history, physical examination, 12-lead electrocardiogram (ECG), laboratory tests, and vital signs.
• •For MD cohort
• •1. Ages 50-85 years, inclusive.
• •2. The participant should be capable of completing assessments alone, per local guidelines.
• •3. Availability of a person ("study partner") who, in the Investigator's judgment, has frequent and sufficient contact with the participant and is able to provide accurate information regarding the participant's cognitive and functional abilities, agrees to provide information at clinic visits, which require partner input for scale completion, and signs the necessary consent form, per local guidelines.
• •4. Clinical diagnosis of probable Alzheimer's disease dementia based on National Institute on Aging Alzheimer's Association criteria.