Scientists launch major study to unravel mysteries of rare brain infection PML

NCT ID NCT01730131

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now This study
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jun 27, 2026 · Last updated Sep 01, 2026 · Updated 11 times

Summary

This study follows 700 people with progressive multifocal leukoencephalopathy (PML), a rare brain infection caused by the JC virus. Researchers will collect blood, spinal fluid, and brain scans over time to understand how the disease progresses. No treatment is given; the goal is to learn more about PML to improve diagnosis and future care.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

What this could lead to
If successful, this study could improve how doctors diagnose and monitor PML, and may point toward future treatment targets.
What could go wrong
This is an observational study, not a treatment trial. It will not directly help participants, and results may take years to influence care.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Participants

About 700 people

The number the study aims to enrol. It can still change while the study runs.

Started

Nov 2012

Lead sponsor

A government research agency

The lead sponsor is the US National Institutes of Health.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Who is studied

Primary clinical for participants that have PML or at risk for PML and community sample/healthy relatives for healthy volunteers.

Ages

2 to 120 years

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

* PML Patients INCLUSION CRITERIA: 1. Suspected or confirmed PML 2. MRI compatible with PML 3. Able to participate in the studies and follow-up required by the protocol 4. At least 2 years old EXCLUSION CRITERIA: 1. Significant condition, which in the judgment of the principal investigator, would make participation in the diagnostic and research parts of evaluation impossible or risky 2. Medical contraindication to MRI (i.e., devices such as a cardiac pacemaker or infusion pump, other metallic implants, metallic foreign objects, body piercings that cannot be removed) 3. Pregnancy 4. Inability to provide informed consent, either directly or via legally authorized representative (LAR) 5. Unwillingness to consent for collection of biological samples or their cryopreservation Control Patients at Risk for PML INCLUSION CRITERIA: 1. Able to participate in the studies and follow-up required by the protocol 2. At least 2 years old 3. Impaired immune function from any cause and considered at risk for PML (i.e.-history of hematological malignancy, chronic inflammatory disease, history of treatment with immune suppressive or immunomodulatory therapies, primary or acquired immunodeficiency syndromes) EXCLUSION CRITERIA: 1. Significant condition, which in the judgment of the principal investigator, would make participation in the diagnostic and research parts of evaluation impossible or risky 2. Medical contraindication to MRI (i.e., devices such as a cardiac pacemaker or infusion pump, other metallic implants, metallic foreign objects, body piercings that cannot be removed) 3. Pregnancy 4. Inability to provide informed consent, either directly or via legally authorized representative (LAR) 5. Unwillingness to consent for collection of biological samples or their cryopreservation Healthy Volunteers INCLUSION CRITERIA: 1. Able to participate in the studies and follow-up required by the protocol 2. At least 18 years old EXCLUSION CRITERIA: 1. Impaired immune function (i.e.-history of hematological malignancy, chronic inflammatory disease, history of treatment with immune suppressive or immunomodulatory therapies, primary or acquired immunodeficiency syndromes) 2. Significant condition, which in the judgment of the principal investigator, would make participation in the diagnostic and research parts of evaluation impossible or risky 3. Medical contraindication to MRI (i.e., devices such as a cardiac pacemaker or infusion pump, other metallic implants, metallic foreign objects, body piercings that cannot be removed) 4. Pregnancy 5. Inability to provide informed consent, either directly or via legally authorized representative (LAR) 6. Unwillingness to consent for collection of biological samples or their cryopreservation

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for Progressive multifocal leukoencephalopathy are added.

Our safety recommendation!

By submitting, you agree to our Terms of use

Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

How to take part

Only the study team decides who joins. These are the ways to reach them.

  1. The places running it

    1 site. The list below names each one and where it is.

  2. The official record

    ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.

    Open the record ↗

  3. A doctor treating you

    A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.

Contacts and locations

Locations

  • National Institutes of Health Clinical Center

    RECRUITING

    Bethesda, Maryland, 20892, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.