CompletedEarly Phase 1

First-in-Human Study for the Safety and Evaluation of Two 4R Tau Ligands as Potential PET Radioligands for Imaging Tau Protein in the Brain

United States11 participantsStarted 2025-11-17

Plain-language summary

This clinical study is being conducted to learn more about two new imaging drugs, called \[18F\]ABBV-964i and \[18F\]ABBV-965i, which are designed to help doctors see changes in the brain related to a condition called Progressive Supranuclear Palsy (PSP). PSP is a rare disease that affects movement, balance, and thinking. These drugs are used with a type of scan called PET (Positron Emission Tomography) to show areas of the brain where a protein called tau builds up. Tau buildup is linked to PSP and other brain diseases. The main goal of this study is to find out if these imaging drugs are safe for people and if they work well to show tau in the brain. The study will also look at how the drugs move through the body and how much radiation they give off. Researchers hope this information will help develop better tools for diagnosing PSP and tracking how it changes over time. Who can join? Adults who are healthy or who have PSP may be able to take part. Participants will have screening tests to make sure they qualify. What does participation involve? People in the study will have PET scans, blood tests, and other safety checks. Some participants will also have an MRI scan. The study is divided into three parts: Part A checks radiation levels in healthy volunteers, Part B looks at how the drugs work in the brain of PSP patients and healthy volunteers, and Part C (optional) repeats scans to see if results are consistent. Why is this important? There is currently no cure for PSP, and better imaging tools could help researchers develop new treatments. By joining this study, participants will help advance research that may improve care for people with PSP and similar conditions in the future.

Who can participate

Age range

18 Years – 80 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Males or females: PSP 40-80 years; HV 18-80 years * Body weight: 43-120 kg (95-265 lb) * Women of childbearing potential: abstinent or use 2 contraception methods (one barrier) during study and 30 days post last injection * Men: use 2 contraception methods and refrain from sperm donation during study and 90 days post last injection * Adequate circulation and normal clotting for arterial cannulation * Sufficient mobility and ability to lie still for imaging * Healthy Volunteers: informed consent, no clinically relevant findings, no cognitive impairment * PSP Participants: informed consent or assent with LAR consent, clinical diagnosis per NINDS-SPSP criteria, MRI consistent with PSP, able to ambulate, tolerate MRI, comply with study procedures, caregiver available if needed Exclusion Criteria: * History of drug or alcohol abuse in past 12 months * Clinically significant lab abnormalities or unstable illness * Investigational drug/device use within 30 days * Pregnant, lactating, or breastfeeding * Significant comorbid conditions (GI, CV, hepatic, renal, etc.) * Abnormal clotting parameters (if arterial sampling) * MRI contraindications (implants, claustrophobia) for PSP participants * Use of OTC meds or supplements within 2 weeks (healthy volunteers) * Use of anti-hemostasis meds within 2 weeks of arterial line placement for PSP participants * Unable to lie still for 90 minutes * Major surgery or significant blood loss within 4 weeks * Positive for Hepa…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Safety of [18F]ABBV-964i and [18F]ABBV-965i: Incidence of Adverse Events

Timeframe: Up to 13 weeks

Radiation dosimetry of [18F]ABBV-964i and [18F]ABBV-965i

Timeframe: Up to 13 weeks

Trial details

NCT IDNCT07348276

SponsorInvicro

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-03-19

View on ClinicalTrials.gov More Progressive Supranuclear Palsy (PSP) trials