An Early Phase 1 interventional study of [18F]ABBV-964i and [18F]ABBV-965i in Progressive Supranuclear Palsy (PSP) and Healthy Participants, sponsored by Invicro. Completed at 1 site in United States. Open to participants aged 18 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-10.
Sponsored by Invicro · Early Phase 1, Interventional, and Diagnostic
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.
This Phase 1, first-in-human study is designed to evaluate the safety, pharmacokinetics, biodistribution, and test-retest variability of two investigational PET radioligands, [18F]ABBV-964i and [18F]ABBV-965i, for imaging 4R Tau pathology in individuals with Progressive Supranuclear Palsy (PSP) and healthy volunteers (HV). The study is structured into three parts: Part A (Dosimetry), Part B (Proof-of-Concept), and Part C (Optional Test-Retest).
Part A involves low-dose whole-body PET imaging in HVs to determine radiation dosimetry using both tracers. Participants will receive intravenous injections of [18F]ABBV-964i and [18F]ABBV-965i in separate imaging sessions, followed by dynamic PET acquisitions and urine collection for dosimetry analysis. Dosimetry calculations will employ MIRD methodology and OLINDA software to estimate absorbed organ doses and effective whole-body dose.
Part B evaluates tracer kinetics and brain uptake in PSP and HV participants using dynamic brain PET imaging over approximately 120 minutes post-injection. Arterial and/or venous blood sampling will be performed for kinetic modeling, including radiometabolite analysis via HPLC and plasma free fraction determination. Quantitative modeling will include compartmental approaches and graphical methods, as well as simplified reference tissue models. Key metrics such as SUV, SUVR, VT, and DVR will be derived to characterize tracer binding and distribution. MRI co-registration will support VOI definition for regional analysis.
Part C, if conducted, will assess test-retest reproducibility of the selected tracer in PSP participants using repeated brain PET scans under similar conditions. Variability will be expressed as percentage difference between test and retest values for primary imaging endpoints.
Radiotracer administration will follow strict safety protocols, including dose limits (≤ 10 mCi per injection) and radiation exposure monitoring to ensure compliance with applicable guidelines. PET imaging will be performed on PET/CT systems with attenuation correction. Image reconstruction will utilize OSEM algorithms with scatter and random corrections applied.
Safety assessments include continuous AE monitoring, vital signs, ECGs, and laboratory evaluations at predefined timepoints. Participants will undergo screening procedures including MRI (for PSP), MMSE, PSPRS, and p-Tau217 plasma testing where applicable. Concomitant medications and procedural details (arterial line placement, Allen's test, infusion protocols) are specified to minimize risk and ensure scientific integrity.
The investigational tracers are formulated as sterile solutions for IV injection. Manufacturing and quality control will adhere to GMP standards. The study rationale emphasizes the need for selective 4R Tau imaging agents to advance diagnostic and therapeutic strategies for PSP and related tauopathies.
171 studies on the registry are indexed under Supranuclear Palsy, Progressive; 51 are open to participants now.
This study's enrollment of 11 is below the median of 43 across 102 interventional studies indexed under Supranuclear Palsy, Progressive.
Browse Supranuclear Palsy, Progressive studies →Invicro is the lead sponsor of 14 studies on the registry; none are open to participants now.
Of its 13 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Healthy participants receive \[18F\]ABBV-964i and \[18F\]ABBV-965i for PET imaging.
Drug: [18F]ABBV-964i · Drug: [18F]ABBV-965i
Participants receive \[18F\]ABBV-964i and \[18F\]ABBV-965i for PET imaging to see how the drugs work in the brain.
Drug: [18F]ABBV-964i · Drug: [18F]ABBV-965i
Participants receive two PET scans using the same drug to see if results are consistent.
Drug: Lead Candidate
PET radiopharmaceuticals selective for tau, administered intravenously at doses up to 10 mCi.
PET radiopharmaceuticals selective for tau, administered intravenously at doses up to 10 mCi.
Preferred PET radiopharmaceuticals (between \[18F\]ABBV-964i and \[18F\]ABBV-965i) selective for tau, administered intravenously at doses up to 10 mCi.
Also known as: [18F]ABBV-965i, [18F]ABBV-964i
Safety of [18F]ABBV-964i and [18F]ABBV-965i: Incidence of Adverse Events
Incidence of adverse events (AEs) following administration of \[18F\]ABBV-964i and \[18F\]ABBV-965i.
Time frame: Up to 13 weeks
Radiation dosimetry of [18F]ABBV-964i and [18F]ABBV-965i
Radiation absorbed dose estimates following administration of \[18F\]ABBV-964i and \[18F\]ABBV-965i, derived from PET imaging and dosimetry calculations.
Time frame: Up to 13 weeks
Brain Uptake measured as Standardized Uptake Value (SUV) or equivalent
Quantitative assessment of uptake in brain regions measured by PET imaging.
Time frame: Up to 13 weeks
Model-derived Pharmacokinetics parameters
Pharmacokinetic parameters of radiotracers derived from dynamic PET imaging and input functions.
Time frame: Up to 13 weeks
Plan to share: Undecided
No publications or documents are linked to this record.
This study is completed, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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Supranuclear Palsy, Progressive →
Invicro