Actively Recruiting
Phase 1 Study to Evaluate [18F]ACI-15916 as a Potential PET Radioligand for Imaging Alpha-synuclein Deposits in the Brain of Patients With Suspected Alpha-synuclein Pathology Compared With Healthy Volunteers
Led by AC Immune SA · Updated on 2025-11-19
46
Participants Needed
1
Research Sites
N/A
Total Duration
On this page
Sponsors
A
AC Immune SA
Lead Sponsor
K
Karolinska Institutet
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are evaluating a new imaging agent called [18F]ACI-15916 to safely and reliably measure the buildup of a protein called alpha-synuclein in the brain. This protein is involved in conditions like Parkinson's disease, Lewy body dementia, and Multiple System Atrophy, collectively known as alpha-synucleinopathies. The study includes both healthy volunteers and people with suspected alpha-synuclein-related diseases to compare protein levels and assess safety and detection accuracy. The study is an open-label, early-phase PET microdose trial involving up to 46 participants divided into four parts. Participants will receive an intravenous injection of [18F]ACI-15916 followed by a PET scan to detect alpha-synuclein deposits. Some will have a second PET scan to test measurement reliability, while others will undergo a whole-body PET-CT scan to estimate radiation dosage. The study includes a screening phase, scanning visits, optional spinal fluid collection, and follow-up safety calls. Participants will visit the clinic for consent, eligibility assessments including physical exams, neurological exams, questionnaires, blood and urine tests, ECG, and in some cases MRI and PET scans with a licensed tracer. During the PET scan, blood samples will be collected, and some may provide spinal fluid. Safety is monitored through follow-up phone calls. The total study duration ranges from 10 to 14 weeks depending on the part of the study the participant is in. Researchers will measure brain uptake of the tracer, adverse events, vital signs, and the reproducibility of PET scan results.
CONDITIONS
Brief Title
[18F]ACI-15916 PET in α-synucleinopathies
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Able to provide written informed consent before any assessments
- Willing and able to comply with study procedures and requirements
- Body mass index between 18 and 31 kg/m2, body weight between 50 and 100 kg
- Female participants not of childbearing potential or agree to use highly effective contraception
- Adequate circulation in the hand for arterial line placement if needed
- Healthy volunteers must be aged 20 or older
- Healthy volunteers must have normal MRI and DAT PET or SPECT results (except Part 4 participants)
- Healthy volunteers must be generally healthy based on medical history, physical exam, vital signs, ECG, and lab tests
- No family history of alpha-synucleinopathy or early-onset neurological disease
- No personal history of significant neurological or psychiatric disorders
- Montreal Cognitive Assessment score of 26 or higher
- No cognitive impairment as judged by physician
- Participants with alpha-synucleinopathies must be aged 40 or older
- Participants with alpha-synucleinopathies diagnosed with idiopathic Parkinson's disease, Parkinson's with genetic risk factors (excluding certain mutations), Dementia with Lewy Bodies, or possible/probable Multiple System Atrophy
- Evidence of dopamine transporter deficit on DAT PET or SPECT imaging
- Medications for symptom treatment must be stable for at least 30 days before screening
You will not qualify if you...
- Female participants who are pregnant, lactating, or breastfeeding
- Psychiatric symptoms interfering with study objectives
- Significant concomitant diseases or conditions within 6 months prior to screening
- History of brain surgery or neurosurgical procedures
- Prior treatment with drug, antibody, or vaccine targeting alpha-synuclein
- Known or suspected drug, alcohol, or other substance abuse
- History of severe or ongoing allergy/hypersensitivity
- Involvement in planning or conduct of the study
- History of significant cardiovascular, pulmonary, renal, hepatic, neurological, mental, or gastrointestinal disorders
- Brain MRI abnormalities excluding alpha-synucleinopathy changes
- Treatment with anticoagulants or antiplatelet drugs except low-dose aspirin within 2 weeks before arterial cannula placement
- High blood pressure above specified limits
- ECG abnormalities including QTc over 450 msec
- Contraindications to MRI, DaT-SPECT, or PET scans
- Prior exposure to high radiation doses
- Treatment with investigational therapies within 30 days or 5 drug half-lives
- Healthy volunteers using CNS active drugs including antidepressants or neuroleptics
- History of neurological diseases interfering with study objectives
- Participants with alpha-synucleinopathy having Parkinsonian syndromes other than idiopathic PD
- Known carriers of certain familial Parkinson's disease gene mutations (PRKN, PINK1, DJ1, LRRK2)
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - Up to 60 days
Participants are screened for eligibility to participate in the trial.
1 screening visit
Duration - 1 day
Participants undergo a PET scan with [18F]ACI-15916 to evaluate alpha-synuclein deposits in the brain, including arterial blood sampling for most participants and safety monitoring.
1 PET scan visit (in-person) with arterial blood sampling; safety phone call after scan
Duration - Up to 1 month after initial scan
For some participants, a second PET scan with [18F]ACI-15916 is performed within one month after the initial scan to assess test-retest variability, followed by safety monitoring.
1 follow-up PET scan visit (in-person); safety phone call after scan
Duration - 1 day
A subset of healthy volunteers undergo a whole-body PET-CT scan to estimate radiation dose after a single administration of [18F]ACI-15916 without arterial blood sampling.
1 whole-body PET-CT scan visit (in-person)
Trial Site Locations
Total: 1 location
1
Karolinska Institutet
Solna, Sweden
Actively Recruiting
Research Team
A
AC Immune SA Clinical Trial Information
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NON_RANDOMIZED
Model
PARALLEL
Primary Purpose
DIAGNOSTIC
Number of Arms
2
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