ABATE

Information about the drug that will be tested in the study

Administration

The vaccine will be administered via a subcutaneous injection (an injection under the skin) at predefined time points.

Is the drug already on the market for another medical condition?

No

Will all participants receive the same drug?

Participants will be selected at random to either receive one of the following options:

• A subcutaneous injection of ACI-24.060
• A subcutaneous injection of placebo (also called a dummy treatment which is an inactive substance identical in appearance to the drug being tested with no active therapeutic effect).

Neither the participant nor his/her doctor will know if the person is receiving the investigational drug or the placebo.

Information about participating in the trial

What are the researchers trying to find out?

The purpose of the study is to evaluate the safety, tolerability and immunogenicity (capability of the vaccine to generate antibodies in participants) and pharmacodynamic effects (the properties of the biological effect generated by the vaccine in participants) of ACI-24.060 in people with prodromal Alzheimer's disease and in people with Down syndrome.

How long will the treatment last?

48 weeks for people with prodromal Alzheimer's disease (Study part 1)

74 weeks for people with Down syndrome (Study part 2)

After the completion of the treatment period, the participants will be followed in the study, respectively up to week 74 in people with prodromal Alzheimer's disease, and up to week 100 in people with Down syndrome.

What your involvement will entail?

• During the study, participants will be asked to complete a test that will assess their suicidal ideation behaviour (this is a test called C-SSRS)
• To complete some laboratory/biological tests (i.e. blood tests) to evaluate the emergent adverse effects (unfavourable signs, symptoms or diseases temporally associated with the use of the drug tested in the study
• To complete other tests that will assess their functioning, cognition and memory (i.e. tests like CDR, RBANS, ADAS-Cog 13, mCRT, CANTAB-PAL)
• Participants will be asked to undertake brain scans (PET, MRI).

Further information on the procedures, tests and number of visits can be obtained from the study team.

Who can participate in this study?

Who can participate in the study?

To take part in the study (part A), participants with prodomal Alzheimer's disease must:

• Be between 50 and 75 years old
• Have evidence of abnormal accumulation of amyloid in their brain (PET scan)
• Have a score of 0.5 in the Clinical Dementia Rating-Global Score (CDR). This would suggest that the person has an impairment in its memory that is at a mild stage
• If the person is taking approved symptomatic medication for dementia (i.e. donepezil, rivastigmine, galantamine or memantine) the dosing regimen must have been stable for at least 2 months prior to the baseline visit.

To take part in the study (part B), participants with Down syndrome must:

• Be 35 to 50 years old. Participants between 35 and 39 years old may be considered on the condition that there is amyloid evidence (at PET and/or in body fluids) compatible with Alzheimer’s disease pathology
• Have a cytogenetic diagnosis of Down syndrome (trisomy 21 or complete unbalanced translocation of the chromosome 21)
• Have mild to moderate intellectual disability as per Diagnostic and Statistical Manual of Mental Disorders (DSM-5) classification.

Participants must have a study partner who has direct and regular contact, at least 10 hours per week, with the participant and who is able to provide reliable answers to questions related to the participant, according to the study investigator.

Who cannot participate in the study?

People cannot take part in the study if they have or have experienced:

• A medical condition that may interfere with the safety and/or efficacy of the study vaccine (e.g. 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)
• History of brain diseases including neurological disorders. A more detailed list can be obtained from the study team
• Any alcohol or drug abuse or dependence within the past 5 years
• Concomitant or past history psychiatric or neurologic disorder other than those considered to be related to Alzheimer’s disease (e.g. head injury with loss of consciousness, symptomatic stroke, Parkinson's disease, severe carotid occlusive disease, transient ischemic attacks hemorrhagic and/or non-hemorrhagic stroke)
• Significant risk of suicide
• Positive HIV test or Active hepatitis B and/or C
• Ongoing treatment with any approved anti-amyloid passive immunotherapy for Alzheimer’s disease
• Previous treatment with ACI-24 or any other active immunotherapy against Alzheimer’s disease
• Use of symptomatic treatments of Alzheimer’s disease (e.g. acetylcholinesterase inhibitors) if not on stable dose for at least 2 months before screening.

The above list is not exhaustive. It includes the most common conditions and diseases that might exclude people from the study.

Information for your doctor

EudraCT Number

2021-006195-17

Clinicaltrials.gov identifier

NCT05462106

Study contact information

clinicaltrials@acimmune.com

+41 21 345 9121

Link to full text

https://clinicaltrials.gov/ct2/show/NCT05462106

The information contained in this document is based on information available on public registries (e.g. clinicaltrials.gov website) on September 2022.

The pharmaceutical company running this trial has reviewed this document.