This is a randomized, double-blind, placebo-controlled first-in-human, Phase 1, safety, tolerability, pharmacokinetic (PK) and preliminary exploratory activity study of escalating multiple intravenous (IV) doses of IBC-Ab002 in persons with early Alzheimer's disease. The study will have both Single- and Multiple-Ascending Dose components.

Subjects in 5 sequential cohorts of 8 subjects each will be assigned in a 3:1 ratio to receive either IBC-Ab002 or matching placebo 4 times. Part A will be a single-ascending dose study and Part B will be a multiple ascending dose study. The two parts of the study will be intercalated such that subjects will be dosed once every 12 weeks. However, repeated dosing at any dose level will not begin until the anticipated cumulative dose for that cohort has been equaled or exceeded in Part A and/or B of the study, and appropriate safety review of data from all preceding doses in prior subjects has taken place. All subjects randomized into Part A of the study will automatically continue into Part B unless dosing is halted at the individual or group level due to safety or other concerns.

Inclusion Criteria:

1. Diagnosis of early Alzheimer's disease based on the National Institute on Aging and Alzheimer's Association) (NIA-AA Research Framework criteria, regardless of apolipoprotein E (APOE) gene status.
2. Able to speak, read and write the local language fluently.
3. With respect to symptomatic treatment for Alzheimer's disease, subjects should either be not treated with any approved treatments for AD or stabilized on approved medication(s) other than anti-Ab antibodies for the treatment of AD for at least 3 months prior to Baseline.
4. Subject has a study partner who spends at least 10 hours/week with the subject, and can attend all visits with the subject, report accurately on the subject's status, and ensure compliance with all study requirements
5. Subject and study partner must each independently be able to understand the study requirements and provide informed consent

Exclusion Criteria:

1. Females who are not postmenopausal at Screening as defined by amenorrhea for at least 12 consecutive months or who have not been sterilized surgically (i.e. bilateral tubal ligation, total hysterectomy, or bilateral oophorectomy, all with surgery at least 1 month before Screening)

2. Other than Alzheimer's disease, any neurologic or medical disorder which may impair cognition.

3. Any contra-indication to undergo magnetic resonance imaging (MRI).

4. Severe vision or hearing impairment that would prevent the subject from performing psychometric tests or otherwise complying with requirements for study participation and activities.

5. History of certain neurological, psychiatric or medical conditions including autoimmune diseases.

6. Clinically significant laboratory or electrocardiogram (ECG) abnormalities

7. Presence of contraindication to lumbar puncture (LP) including taking anticoagulant or antiplatelet medications other than aspirin at a dose of ≤ 100 mg/day or clopidogrel.

8. Taking any of the following medications.

   1. Immunosuppressant medications, including chronic systemic corticosteroids (chronic use of topical steroids is allowed)
   2. Injected or infused antibody therapies, including but not limited to antibodies directed against tumor necrosis factor (TNF), anti-interleukin-6 (anti-IL-6), natalizumab, rituximab and similar agents
   3. Aducanumab, (aducanumab-avwa) intravenous injection (brand name: Aduhelm™), or any other experimental or approved anti-amyloid antibody
   4. Insulin
   5. Anticoagulant or anti-platelet medications including warfarin, heparinoids and direct coagulation factor inhibitors (e.g. apixaban, dabigatran, rivaroxaban) within 90 days of the planned first dose of study drug; either aspirin at a dose of < 100 mg/day or clopidogrel at a dose of 75 mg/day, but not both in combination is permitted

9. Participation in any other interventional clinical trial, or treatment with any investigational drug or investigational use of an approved therapy, within 30 days or 5 half-lives of such agent, whichever is longer, prior to the first Screening visit

10. Subject currently smokes more than 5 cigarettes or equivalent tobacco consumption daily

11. Regular nonmedical use of cannabis or cannabis products unless such products are documented by the manufacturer's label not to contain tetrahydrocannabinol or its derivatives or analogs

12. History of drug (including cannabis) or alcohol abuse within the last 5 years

13. Positive urine drug test for drugs of abuse at Screening. Subjects who test positive for benzodiazepines or opioids in urine drug testing need not be excluded if in the clinical opinion of the investigator, this is due to the subject taking prior/concomitant medications containing benzodiazepines or opioids for a medical condition and not due to drug abuse

14. Subjects who answer "yes" to Columbia Suicidality Rating Scale (C-SSRS) suicidal ideation Type 4 or 5, or any suicidal behavior assessment within 6 months before Screening, at Screening, or has been hospitalized or treated for suicidal behavior in the past 5 years before Screening

15. Unwillingness to comply with study requirements or history of noncompliance in prior clinical trials

Individual study data will be shared with qualified researchers upon review of the request by the trial sponsor

After the end of the study, submission of the clinical study report and publication of the study results

Upon review of the qualifications of the requesting researcher and the purpose of the research