A Study to Assess the Effects of ACI-24.060 in Alzheimer's Disease and in Down Syndrome (ABATE Study)

NCT ID: NCT05462106

Last Updated: 2025-12-15

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE1/PHASE2

Total Enrollment

176 participants

Study Classification

INTERVENTIONAL

Study Start Date

2022-06-21

Study Completion Date

2026-06-30

Brief Summary

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The purpose of this study is to assess the safety, tolerability, immunogenicity and pharmacodynamic effects of ACI-24.060 in subjects with prodromal Alzheimer's disease and in non-demented adults with Down syndrome.

Detailed Description

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This phase 1b/2 study will be in 2 parts. Study Part 1 will involve subjects with prodromal Alzheimer's disease. Study Part 2 will involve subjects with Down syndrome.

Conditions

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Amyloid Plaque Beta-Amyloid DSAD Prodromal Alzheimer's Disease Alzheimer's Disease

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

SEQUENTIAL

Primary Study Purpose

TREATMENT

Blinding Strategy

TRIPLE

Participants Investigators Outcome Assessors

Study Groups

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Placebo for Study Part 1 (Prodromal AD)

Prodromal AD participants receive placebo at predefined time points over 48 weeks

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type BIOLOGICAL

Administration of Placebo

ACI-24.060 at Dose A in Prodromal AD

Prodromal AD participants receive dose A of ACI-24.060 at predefined time points over 48 weeks

Group Type EXPERIMENTAL

ACI-24.060 at Dose A

Intervention Type BIOLOGICAL

Administration of Dose A of ACI-24.060

ACI-24.060 at Dose B in Prodromal AD

Prodromal AD participants receive dose B of ACI-24.060 at predefined time points over 48 weeks.

Group Type EXPERIMENTAL

ACI-24.060 at Dose B

Intervention Type BIOLOGICAL

Administration of Dose B of ACI-24.060

ACI-24.060 at Dose C in Prodromal AD

Prodromal AD participants receive dose C of ACI-24.060 at predefined time points over 48 weeks.

Group Type EXPERIMENTAL

ACI-24.060 at Dose C

Intervention Type BIOLOGICAL

Administration of Dose C of ACI-24.060

ACI-24.060 at Dose D in Prodromal AD (Optional)

Prodromal AD participants receive dose D of ACI-24.060 at predefined time points over 48 weeks. This arm is optional.

Group Type EXPERIMENTAL

ACI-24.060 at Dose D

Intervention Type BIOLOGICAL

Administration of Dose D of ACI-24.060

Placebo for Study Part 2 (Down syndrome)

Participants with Down syndrome receive placebo at predefined time points over 74 weeks

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type BIOLOGICAL

Administration of Placebo

ACI-24.060 at Dose A in Down syndrome

Participants with Down syndrome receive dose A of ACI-24.060 at predefined time points over 74 weeks. Dose A will be a dose already tested in Study Part 1.

Group Type EXPERIMENTAL

ACI-24.060 at Dose A

Intervention Type BIOLOGICAL

Administration of Dose A of ACI-24.060. Dose A will be a dose already tested in Study Part 1

ACI-24.060 at Dose B in Down syndrome

Participants with Down syndrome may optionally receive a dose B of ACI-24.060 at predefined time points over 74 weeks.

Group Type EXPERIMENTAL

ACI-24.060 at Dose B

Intervention Type BIOLOGICAL

Administration of Dose B of ACI-24.060

ACI-24.060 at Dose C in Down syndrome

Participants with Down syndrome receive dose C of ACI-24.060 at predefined time points over 74 weeks. Dose C will be a dose already tested in Study Part 1.

Group Type EXPERIMENTAL

ACI-24.060 at Dose C

Intervention Type BIOLOGICAL

Administration of Dose C of ACI-24.060

Interventions

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Placebo

Administration of Placebo

Intervention Type BIOLOGICAL

ACI-24.060 at Dose A

Administration of Dose A of ACI-24.060

Intervention Type BIOLOGICAL

ACI-24.060 at Dose B

Administration of Dose B of ACI-24.060

Intervention Type BIOLOGICAL

ACI-24.060 at Dose C

Administration of Dose C of ACI-24.060

Intervention Type BIOLOGICAL

ACI-24.060 at Dose D

Administration of Dose D of ACI-24.060

Intervention Type BIOLOGICAL

Placebo

Administration of Placebo

Intervention Type BIOLOGICAL

ACI-24.060 at Dose A

Administration of Dose A of ACI-24.060. Dose A will be a dose already tested in Study Part 1

Intervention Type BIOLOGICAL

ACI-24.060 at Dose B

Administration of Dose B of ACI-24.060

Intervention Type BIOLOGICAL

ACI-24.060 at Dose C

Administration of Dose C of ACI-24.060

Intervention Type BIOLOGICAL

Eligibility Criteria

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Inclusion Criteria

Study Part 1

1. Age ≥50 and ≤85 years at screening.
2. Diagnosis of prodromal AD: MCI due to AD according to National Institute on Aging Alzheimer's Association (NIA-AA) criteria.
3. PET scan at screening consistent with the presence of amyloid pathology.
4. Clinical Dementia Rating (CDR)-Global Score of 0.5.
5. Subjects either not taking any marketed treatment for AD or receiving a stable dose of an acetylcholinesterase inhibitor (ACHEI) and/or memantine for at least 2 months prior to baseline.

Study Part 2

1. Age ≥35 and ≤50 years at screening (subjects with DS with age ≥35 and ≤39 years may be considered on the condition that there is prior evidence of amyloid results compatible with AD pathology at PET-scan and/or in biofluids).
2. Male or female subjects with DS with a cytogenetic diagnosis being either trisomy 21 or complete unbalanced translocation of the chromosome 21.
3. PET scan at screening consistent with the presence of amyloid pathology.
4. Mild to moderate intellectual disability as per Diagnostic and Statistical Manual of Mental Disorders (DSM-5) classification.
5. Subjects must have a study partner who has direct and regular contact, at least 10 hours per week, with the subject and who is able to provide reliable answers to questions related to the subject, according to the study investigator.

Exclusion Criteria

1. Any unstable and/or clinically significant medical condition likely to hamper the evaluation of safety and/or efficacy of the study treatment (eg, moderate and/or severe untreated obstructive sleep apnea, clinically significant reduction in serum B12 or folate levels, clinically significant abnormalities of thyroid function, stroke, or other cerebrovascular conditions), as per investigator's judgement.
2. DSM-5 criteria for drug or alcohol abuse or dependence currently met within the past 5 years.
3. History or presence of uncontrolled seizures. If history of seizures, they must be well controlled with no occurrence of seizures in the 2 years before study screening. The use of antiepileptic medications is permitted.
4. Concomitant or past history psychiatric or neurologic disorder other than those considered to be related to AD (eg, head injury with loss of consciousness, symptomatic stroke, Parkinson's disease, severe carotid occlusive disease, transient ischemic attacks \[TIAs\], hemorrhagic and/or non-hemorrhagic stroke).
5. History of meningitis or meningoencephalitis.
6. History of moderate or severe traumatic brain injury.
7. History of or presence of inflammatory neurological disorders.
8. History or presence of immunological or autoimmune disorders.
9. History of severe allergic reaction (eg, anaphylaxis) including, but not limited to severe allergic reaction to previous vaccines, foods, and/or medications.
10. Significant risk of suicide, defined using the C-SSRS as the subject answering "yes" to suicidal ideation questions 4 or 5 or answering "yes" to suicidal behavior within the past 12 months.
11. MRI scan at screening showing a single area of cerebral vasogenic edema, superficial siderosis, or evidence of a previous macro-hemorrhage or showing more than 4 cerebral microhemorrhages (regardless of their anatomical location or diagnostic characterization as "possible" or "definite"). Evidence of space occupying lesions other than benign meningioma of less than 1 cm diameter, more than 2 lacunar infarcts, or 1 single infarct larger than 1 cm in diameter. Screening MRI scan showing structural evidence of alternative pathology not consistent with AD and is considered to be at the origin of subject's symptoms.
12. Deviations from normal values for hematologic parameters, liver function tests, and other biochemical measures, judged to be clinically significant by the investigator.
13. Subjects with a positive Human Immunodeficiency Virus (HIV-1 and 2) test at screening.
14. Subjects with clinical or laboratory evidence of active hepatitis B or C at screening (eg, HBV or HCV antigens).
15. Subjects with positive syphilis serology consistent with active syphilis at screening.
16. Subjects with presence of antibody titers related to immunological or autoimmune disorders at screening.
17. MRI examination cannot be done for any reason, including but not limited to metal implants contraindicated for MRI and/or severe claustrophobia.
18. Any contraindication for PET scan imaging.
19. Any contraindication to lumbar puncture in subjects undergoing this procedure (note: lumbar puncture is optional in subjects with DS).
20. Previous treatment with ACI-24 or any other active immunotherapy against AD at any time in the past unless there is firm evidence that the subject received placebo only and the placebo formulation is not expected to induce any specific immune response.
21. Previous treatment with any investigational and/or marketed passive immunotherapy against AD within 6 months before screening or 5 half-lives, whichever is longer, unless there is firm evidence that the subject received placebo only.
22. Ongoing treatment with any approved anti-amyloid passive immunotherapy for Alzheimer's disease.
23. Use of acetylcholinesterase inhibitor or glutamatergic drugs (eg, memantine, topiramate, lamotrigine) if not on stable dose for at least 2 months before screening.
24. Any vaccine, either live or not, including but not limited to influenza or COVID-19 vaccine, received within 4 weeks before randomization.
25. Subjects with treated hypothyroidism not on a stable dose of replacement medication for at least 2 months before screening and having clinically significant abnormal serum T4 and/or thyroid stimulating hormone at screening.
26. Subjects undergoing lumbar puncture and being treated with any anticoagulants or antiplatelet drugs, except aspirin at doses of 100 mg daily or lower.
27. Use of antidepressants (other than selective serotonin reuptake inhibitors/serotonin-norepinephrine reuptake inhibitors at stable dose); typical antipsychotics; γ-aminobutyric acid agonists (eg, gabapentin); or stimulants (eg, methylphenidate, modafinil). Stable doses of atypical antipsychotics or benzodiazepines are only allowed if this is not considered to influence the safety and the efficacy of the study treatment according to the site investigator and the sponsor medical monitor.
28. Chronic use of opioid analgesics. A limited treatment duration for acute conditions until 24 hours before cognitive assessment is allowed.
29. Current use of immunosuppressant or immunomodulating drugs or their use within the 6 months before study screening. Current use of oral steroids or their use within the 3 months before study screening.


30. Clinical diagnosis of AD dementia in DS as per International Classification of Diseases 10 (ICD-10).
31. DSQIID \>20.
32. Intelligence quotient score \<40 (KBIT-2).
Minimum Eligible Age

35 Years

Maximum Eligible Age

85 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Worldwide Clinical Trials

OTHER

Sponsor Role collaborator

AC Immune SA

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Michael Rafii, MD

Role: PRINCIPAL_INVESTIGATOR

University of Southern California, Alzheimer's Therapeutic Research Institute, 9860 Mesa Rim Rd, San Diego, CA 92121, USA

Locations

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Barrow Neurological Institute

Phoenix, Arizona, United States

Site Status RECRUITING

Indiana University / IU Health

Indianapolis, Indiana, United States

Site Status RECRUITING

University of Kansas Medical Center Research Institute

Fairway, Kansas, United States

Site Status RECRUITING

Massachusetts General Hospital

Boston, Massachusetts, United States

Site Status RECRUITING

The Washington University

St Louis, Missouri, United States

Site Status RECRUITING

Vanderbilt University Medical Center

Nashville, Tennessee, United States

Site Status RECRUITING

UT Health San Antonio

San Antonio, Texas, United States

Site Status RECRUITING

Fundació ACE, Institut Català de Neurociències Aplicades

Barcelona, , Spain

Site Status RECRUITING

Hospital de la Santa Creu i Sant Pau

Barcelona, , Spain

Site Status RECRUITING

Hospital Universitario Virgen De Las Nieves

Granada, , Spain

Site Status WITHDRAWN

Hospital Clínico San Carlos

Madrid, , Spain

Site Status RECRUITING

Hospital Universitario de la Princesa

Madrid, , Spain

Site Status RECRUITING

Hospital Universitario Marqués de Valdecilla

Santander, , Spain

Site Status RECRUITING

Hospital Universitario y Politécnico La Fe

Valencia, , Spain

Site Status RECRUITING

Cambridge and Peterborough NHS Foundation Trust - Windsor Research Units

Cambridge, , United Kingdom

Site Status RECRUITING

Liverpool University Hospitals NHS Foundation Trust

Liverpool, , United Kingdom

Site Status RECRUITING

Re:Cognition Health Limited

London, , United Kingdom

Site Status RECRUITING

South London and Maudsley NHS Foundation Trust of The Maudsley Hospital

London, , United Kingdom

Site Status RECRUITING

Oxford Health NHS Foundation Trust

Oxford, , United Kingdom

Site Status RECRUITING

Countries

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United States Spain United Kingdom

Central Contacts

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Benedicte Le

Role: CONTACT

+41 21 345 9121

Olivier Sol, MD

Role: CONTACT

+41 21 345 9121

Other Identifiers

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2021-006195-17

Identifier Type: EUDRACT_NUMBER

Identifier Source: secondary_id

2022-500069-29-00

Identifier Type: OTHER

Identifier Source: secondary_id

ACI-24-AD-DS-2102

Identifier Type: -

Identifier Source: org_study_id

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