Clinical trials

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.

The main purposes of this study are: * to investigate the safety and tolerability of ACI-19764 when it is administered to healthy participants * to determine how quickly and to what extent ACI-19764 is absorbed, transported, metabolized, and excreted by the body (fasted and after a meal) * to determine the effect of ACI-19764 on specific markers in the blood that are part of the immune system The effects of ACI-19764 will be compared with the effects of a placebo. ACI-19764 is a brain-penetrant NLRP3 inhibitor. The study consists of 2 parts, Part A (SAD, single ascending dose) and Part B (MAD, multiple ascending doses). Participants in Part A will receive the study compound once and participants in Part B will receive the study compound multiple times (daily over 14 days). Each of these 2 study parts will be divided into different groups of participants to test different doses of ACI-19764.

The goal of this clinical trial is to test whether we can reliably and safely measure the accumulation of pathological protein α-synuclein \[involved in some diseases such as Parkinson's disease, Lewy body dementia and Multiple System Atrophy (MSA), collectively named α-synucleinopathies\] using a new positron emission tomography (PET) tracer called \[18F\]ACI-15916. Both healthy people and people with (suspected) α-synuclein pathology will participate to this trial. The main questions it aims to answer are: * whether \[18F\]ACI-15916 is safe and well tolerated when injected into participants * whether \[18F\]ACI-15916 reliably detects α-synuclein in the brain using PET technique. * whether there are differences in the amount of this protein between people with diseases related to α-synuclein accumulation in the brain and people without these diseases. Participants will: * Visit the clinic to consent to their participation and to ensure they are eligible \[physical and neurological examinations, questionnaires, blood and urine tests, ECG and in some cases a MRI and a PET scan with a licensed tracer (\[18F\]FE-PE2I) to confirm or not the disease\]. * Visit the clinic to receive the tracer \[18F\]ACI-15916 intravenously and be scanned in a PET scanner, during which blood will be collected (and optionally spinal fluid). * Receive a phone call from the clinic 1 week after the PET scan to report any symptoms and side-effects that they may be having. Some of the participants may be asked to come again to the clinic for a second PET scan with \[18F\]ACI-15916, allowing the researchers to determine if the measurements with the first PET scan are stable and reproducible. Some of the participants will participate in a specific part of the study to evaluate the distribution of the PET ligand in the whole body, with a similar visit schedule.

The goal of this clinical trial is to test whether we can reliably and safely measure the accumulation of pathological protein TDP-43 \[involved in rare forms of dementia such as frontotemporal dementia (FTD) and in amyotrophic lateral sclerosis (ALS)\] using a new positron emission tomography (PET) tracer called \[18F\]ACI-19626. Both healthy people and people with (suspected) TDP-43 accumulation will participate to this trial. The main questions it aims to answer are: * whether \[18F\]ACI-19626 is safe and well tolerated when injected into participants * whether \[18F\]ACI-19626 reliably detects abnormal TDP-43 in the brain using PET technique. * whether there are differences in the amount of this protein between people with diseases related to TDP-43 accumulation in the brain and people without these diseases. Participants will: * Visit the clinic to consent to their participation and to ensure they are eligible (physical and neurological examinations, questionnaires, blood and urine tests, ECG and MRI in some cases). * Visit the clinic to receive the tracer \[18F\]ACI-19626 intravenously and be scanned in a PET scanner, during which blood will be collected. * Receive a phone call from the clinic 2 to 4 days after the PET scan to report any symptoms and side-effects that they may be having. Some of the participants may be asked to come again to the clinic for a second PET scan, allowing the researchers to determine if the measurements with the first PET scan are stable and reproducible.