A Phase 1 interventional study of 89 Zr-Df-crefmirlimab in Progressive Multifocal Leukoencephalopathy, Multiple Sclerosis and Other Neuroinflammatory Diseases With BBB Leakage, sponsored by National Institute of Neurological Disorders and Stroke (NINDS). Recruiting at 1 site in United States. Open to participants aged 18 Years to 120 Years. Per ClinicalTrials.gov, last updated 2026-06-05.
Sponsored by National Institute of Neurological Disorders and Stroke (NINDS) · Phase 1, Interventional, and Treatment
Background:
Multiple sclerosis (MS) and progressive multifocal leukoencephalopathy (PML) are disorders that affect the central nervous system (CNS). The CNS includes the brain, spinal cord, and optic nerves. Both diseases can cause muscle weakness and impair vision, speech, and coordination. Researchers are working to better understand how MS and PML affect the CNS.
Objective: To test whether an experimental radioactive tracer (minibody) can help positron emission tomography (PET) scans detect certain immune cells in the CNS of people with MS and PML.
Eligibility:
People aged 18 years and older with MS, other neuroinflammatory diseases with BBB leakage, or PML.
Design:
Participants will come to the clinic for at least 3 visits over 4 to 6 weeks.
Participants will undergo testing. They will have a physical and neurological exam. They will have blood tests and tests of their heart function. They will have a magnetic resonance imaging (MRI) scan of the brain. They may have a spinal tap: Their lower back will be numbed, and a needle will be inserted between the bones of the spine to withdraw fluid from around the spinal cord.
Minibody is given through a tube with a needle placed in a vein in the arm. This takes 5 to 10 minutes. Participants will have heart function tests before and after receiving the minibody.
Participants may have a PET scan on the day of the Minibody and will return the next day for another PET scan. They will lie on a table that moves through a doughnut-shaped machine. This scan will take about 1 hour.
Participants with PML may opt to repeat the minibody infusion and the PET scan within 6 months.
Study Description:
This study will obtain pilot data for noninvasive positron emission tomography (PET) imaging of CD8 plus T lymphocytes in two inflammatory central nervous system (CNS) demyelinating diseases, multiple sclerosis (MS) and progressive multifocal leukoencephalopathy (PML), and other neuroinflammatory diseases by characterizing CNS uptake of anti-CD8 plus T cell antibody fragment (aka minibody ) (89Zr-Df-crefmirlimab), an investigational, intravenous PET tracer.
Objectives:
Primary Objective: To detect and localize infiltration of CD8 plus T cells in the CNS of adults with MS and PML via PET-CT (computed tomography) scans using a minibody with high affinity for CD8 plus T cells.
Secondary Objectives: (1) To characterize safety and tolerability of 89Zr-Df-crefmirlimab in the participant population. (2) For the PML cohort with longitudinal evaluation, to determine the effects of immune reconstitution, either spontaneous or facilitated, on 89Zr-Dfcrefmirlimab uptake. (3) To determine whether 89Zr-Df-crefmirlimab uptake profile is disease specific for MS and PML.
Endpoints:
Primary Endpoints: Standardized uptake values (SUV) in different tissue types (lesions, white matter, gray matter, meninges, choroid plexus, as determined from coregistered MRI) in each cohort (MS or PML) by region-of-interest (ROI) analysis.
Secondary Endpoints: (1) Frequency and nature of adverse events; (2) For the PML cohort with longitudinal evaluation, changes in SUV over time. (3) Compare patterns of uptake distribution across PML, MS, and other neuroinflammatory diseases with BBB leakage.
29 studies on the registry are indexed under Leukoencephalopathy, Progressive Multifocal; 7 are open to participants now.
This study's planned enrollment of 15 is below the median of 24 across 15 interventional studies indexed under Leukoencephalopathy, Progressive Multifocal.
Browse Leukoencephalopathy, Progressive Multifocal studies →National Institute of Neurological Disorders and Stroke (NINDS) is the lead sponsor of 601 studies on the registry; 56 are open to participants now.
Of its 18 completed or terminated interventional studies of FDA-regulated products, 8 (44%) 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.
In order to be eligible to participate in this study, an individual must meet all of the following criteria:
Multiple Sclerosis Inclusion Criteria
PML Inclusion Criteria
Patients with Known or Suspected Neuroinflammatory Diseases and Evidence of Open BBB Inclusion Criteria
-Clinical evaluation suggesting an inflammatory disorder of the central nervous system other than MS or PML. Other confirmed neuroinflammatory disorders may include -MOGAD, NMOSD, Behcet's syndrome, and neurosarcoidosis. Unconfirmed, though
suspected cases of neuroinflammation may also be included.
EXCLUSION CRITERIA:
An individual who meets any of the following criteria will be excluded from participation in this study:
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.
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.
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.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask 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.
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.
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.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Reproductive potential
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask 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.
MS cohort- Up to four study visits. (1) Baseline; (2) Day 0: MRI brain/spinal cord (with gadolinium) followed by an intravenous injection of anti-CD8 minibody (aka"PET/CT tracer"); (3) Day 1: PET/CT scan(4) Optional Visit: PET/CT scan
Drug: 89 Zr-Df-crefmirlimab
Up to four study visits: (1) Baseline; (2) Day 0: MRI brain/spinal cord (with gadolinium) followed by an intravenous injection of anti-CD8 minibody (aka "PET/CT tracer"); (3) Day 1: PET/CT scan(4) Optional Visit: PET/CT scan
Drug: 89 Zr-Df-crefmirlimab
PML cohort- Up to seven study visits. (1) Baseline; (2) Day 0: MRI brain (with gadolinium) followed by an intravenous injection of anti-CD8 minibody (aka "PET/CT tracer"); (3) Day 1: PET/CT scan; (4) Study visit 4 (optional): PET/CT scan. (5) Study visit 5 (optional; time-period between study visit 3 and 5 is variable based on radiological criteria): MRI brain (with gadolinium) followed by an intravenous injection of anti-CD8 minibody (aka "PET/CT tracer"); (6) Study visit 6: PET/ CT scan; (7) Study visit 7: PET/CT scan.
Drug: 89 Zr-Df-crefmirlimab
an 80 kDa minibody (Mb) with high affinity to CD8 glycoprotein (binding EC50 = 0.4 nM) that is conjugated with deferoxamine (Df) and radiolabeled with the positron emitting radionuclide, Zr-89 (T1/2 78.4 hours).
Infiltration of CD8+ T cells in the CNS of adults with MS and PML via PET-CT scans using a minibody with high affinity for CD8+ T cells.
To detect and localize infiltration of CD8+ T cells in the CNS of adults with MS and PML via PET-CT scans using a minibody with high affinity for CD8+ T cells.
Time frame: Day 1 Study Visit
For the PML cohort with longitudinal evaluation, effects of immune reconstitution, either spontaneous or facilitated, on 89Zr-Dfcrefmirlimab uptake.
Comparison of SUV before and after immune reconstitution, either spontaneous or facilitated (for participants with optional follow-up imaging).
Time frame: up to 6 months after first PET/CT scan
Safety of 89Zr-Dfcrefmirlimab in the participants with CNS disease.
To assess the safety of 89Zr-Dfcrefmirlimab in participants with CNS disease.
Time frame: At each study visit
To determine whether 89Zr-Df-crefmirlimab uptake profile in MS and PML is disease-specific.
Understand the physiological pattern of 89Zr-Df-crefmirlimab distribution corresponding to normal accumulation of CD8+ T cells.
Time frame: Comparison of pattern of PET uptake distribution and SUV profiles in MS, PML, and other neuroinflammatory diseases with BBB leakage.
Plan to share: Undecided
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Studies of the drug tested here: Zirconium Zr 89 Crefmirlimab Berdoxam
Leukoencephalopathy, Progressive Multifocal →
National Institute of Neurological Disorders and Stroke (NINDS) →