Phase 2 Alzheimer's Disease Trial, Recruiting

Written by an AI model from ClinicalTrials.gov eligibility criteria and checked on a sample basis. Please confirm against the original criteria.

Who might be able to join this trial:

For Part 1 of the trial (general Alzheimer's disease group):

• People aged 50 to 85 years old at the time of screening
• People who have been diagnosed with mild cognitive impairment (early-stage memory and thinking problems) believed to be caused by Alzheimer's disease, based on recognised medical guidelines
• People whose brain scan (PET scan) shows signs of amyloid, a protein linked to Alzheimer's disease
• People with a Clinical Dementia Rating score of 0.5, which indicates very mild cognitive changes
• People who are either not taking any Alzheimer's medications, or who have been taking a stable dose of certain Alzheimer's medications (acetylcholinesterase inhibitors and/or memantine) for at least 2 months before screening

For Part 2 of the trial (Down syndrome group):

• People aged 35 to 50 years old at the time of screening (people aged 35 to 39 may be considered if there is already evidence of amyloid consistent with Alzheimer's disease from a prior brain scan or biological fluid test)
• People who have Down syndrome confirmed by genetic testing, specifically trisomy 21 or a complete unbalanced translocation of chromosome 21
• People whose brain scan (PET scan) shows signs of amyloid consistent with Alzheimer's disease
• People who have mild to moderate intellectual disability as defined by standard psychiatric guidelines (DSM-5)
• People who have a study partner — such as a carer, family member, or support person — who has direct and regular contact with them for at least 10 hours per week and can reliably answer questions about them on their behalf

Who may not be able to join:

• People with an unstable or significant medical condition that could interfere with the trial, such as untreated moderate or severe sleep apnoea, low vitamin B12 or folate levels, thyroid problems, stroke, or other conditions affecting blood flow to the brain (confirm with trial site)
• People who have met the criteria for a substance use disorder involving drugs or alcohol at any point in the past 5 years (tobacco use disorder is not excluded)
• People with a history of seizures that are not well controlled, or who have had a seizure within the 2 years before screening (people whose seizures are well controlled and seizure-free for 2 years may still be considered)
• People with a significant psychiatric or neurological condition unrelated to Alzheimer's disease, such as Parkinson's disease, serious head injury with loss of consciousness, or stroke; people with a history of major depression may still be considered if they have had no major episodes for at least 1 year before screening
• People with a history of meningitis or brain infection (meningoencephalitis)
• People with a history of moderate or severe traumatic brain injury
• People with a history or current presence of inflammatory neurological disorders
• People with a history or current presence of immune system or autoimmune disorders
• People with a history of a severe allergic reaction, such as anaphylaxis, including reactions to vaccines, food, or medications
• People assessed as having a significant risk of suicide based on a standardised assessment tool used in the trial
• People whose MRI brain scan at screening shows certain abnormalities, including brain swelling, bleeding, more than 4 small bleeds, significant lesions, more than 2 small strokes, or signs of a condition other than Alzheimer's disease that could explain their symptoms
• People with blood test results showing significant abnormalities in blood counts, liver function, or other measures, as judged by the investigating doctor
• People who test positive for HIV at screening
• People who show signs of active hepatitis B or C infection at screening
• People who test positive for active syphilis at screening
• People whose blood tests show antibodies associated with immune or autoimmune conditions at screening
• People who are unable to have an MRI scan for any reason, including metal implants incompatible with MRI or severe claustrophobia
• People who have any medical reason that prevents them from having a PET scan
• People who have any medical reason that prevents them from having a lumbar puncture (spinal fluid test), where this procedure is required (note: lumbar puncture is optional for people in the Down syndrome group)
• People who have previously been treated with ACI-24 or any other active vaccine-type treatment targeting Alzheimer's disease, unless there is clear evidence they received only a placebo
• People who have received a passive immunotherapy (antibody-based treatment) for Alzheimer's disease within 6 months before screening, or within 5 half-lives of that treatment, whichever is longer — unless there is clear evidence they received only a placebo
• People who are currently receiving an approved anti-amyloid antibody treatment for Alzheimer's disease
• People taking certain Alzheimer's or brain-related medications (such as acetylcholinesterase inhibitors, memantine, topiramate, or lamotrigine) who have not been on a stable dose for at least 2 months before screening
• People who have received any vaccine — including flu or COVID-19 vaccines — within 4 weeks before being assigned to a treatment group
• People with treated hypothyroidism who have not been on a stable dose of thyroid medication for at least 2 months before screening, and who have abnormal thyroid blood test results at screening
• People who need a lumbar puncture and are taking blood-thinning or antiplatelet medications, except for low-dose aspirin (100 mg per day or less)
• People taking certain psychiatric or neurological medications, including some antidepressants (other than SSRIs or SNRIs at stable dose), typical antipsychotics, certain nerve pain medications such as gabapentin, or stimulants such as methylphenidate or modafinil; stable doses of some other medications may be allowed depending on the trial doctor's and sponsor's assessment (confirm with trial site)
• People who regularly use opioid-based pain medications (limited short-term use for an acute condition, ending at least 24 hours before a thinking and memory assessment, may be permitted)
• People who are currently using, or have used within the past 6 months, immune-suppressing or immune-modifying medications; or who have used oral steroids within the past 3 months

Additional exclusions for Part 2 (Down syndrome group only), assessed at the time of treatment assignment:

• People who have already received a clinical diagnosis of Alzheimer's disease dementia in Down syndrome according to standard diagnostic criteria
• People who score above 20 on a specific assessment tool used to measure dementia-related changes in Down syndrome (DSQIID) (confirm with trial site)
• People who score below 40 on a standardised cognitive ability test (KBIT-2) (confirm with trial site)

Important: Always verify eligibility with the trial site directly before applying.