Clinical trial Recruiting at 7 sites Phase 1 Interventional Ages 2 to 17 Men only

Evaluating a new treatment for Pelizaeus-Merzbacher Disease in children

Official title: A Phase 1b Study to Evaluate the Safety, Pharmacokinetics and Pharmacodynamics of Intrathecally Administered ION356 in Patients With Pelizaeus Merzbacher Disease

Run by Ionis Pharmaceuticals, Inc. · NCT06150716 · Data updated 2026-11-12

This study is testing a new drug called ION356 to see if it is safe and tolerable for children with Pelizaeus-Merzbacher Disease who have a specific genetic change.

More Pelizaeus-Merzbacher Disease trials

Quick facts

PhasePhase 1
Study typeInterventional
Ages2 Years to 17 Years
SexMen only
Enrollment24 (estimated)
SponsorIonis Pharmaceuticals, Inc.
Industry-sponsored
Locations7 sites (Atlanta, Georgia and 6 other locations)
StatusRecruiting
StartedApril 10, 2024
Main results expectedJune 2028
Study endsJune 2028
Registry record updatedDecember 12, 2025
Trial IDNCT06150716 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are male children aged 2 to 17 years with a confirmed diagnosis of PMD and PLP1 gene duplication.

Probably not a fit

Patients with significant medical abnormalities or those unwilling to comply with study procedures may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study aims to assess the safety and tolerability of ION356, an investigational drug, in pediatric participants diagnosed with Pelizaeus-Merzbacher Disease (PMD) who have a genetic confirmation of PLP1 gene duplication. It is designed as a Phase 1b, open-label multiple-ascending dose study involving approximately 24 children. Participants will receive escalating doses of ION356 over a 48-week period, followed by a long-term extension phase lasting 109 weeks to monitor ongoing effects and safety. The study will involve regular assessments and follow-ups to ensure compliance and gather feedback on the treatment's impact.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for children suffering from Pelizaeus-Merzbacher Disease.

How similar studies have gone: While this approach is novel, similar studies targeting genetic conditions have shown promise in the past.

Who can join: the full rules

Show full inclusion / exclusion criteria
Key Inclusion Criteria

1. Participant's parent or legally accepted representative can provide informed consent, attend all scheduled study visits, provide feedback regarding the participant's symptoms, and can comply with all study requirements.
2. Diagnosis of PMD with genetic confirmation of PLP1 gene duplication.
3. Clinical phenotype and brain imaging consistent with a diagnosis of PMD.
4. Male between the ages of 2 and 17 years, inclusive, at the time of informed consent.
5. Able and willing to meet all study requirements (in the opinion of the Investigator), including travel to Study Center, procedures, measurements, and visits.

Exclusion Criteria

1. Clinically significant abnormalities in medical history, laboratory tests or physical examination.
2. Unwillingness to comply with study procedures, including follow-up, as specified by this protocol, or unwillingness to cooperate fully with the Investigator.
3. Any contraindication or unwillingness to undergo magnetic resonance imaging (MRI).
4. Treatment with another investigational drug, biological agent, or device within 1 month of Screening, or 5 half-lives of the investigational agent, whichever is longer.
5. Previous treatment with an oligonucleotide (including small interfering ribonucleic acid) within 4 months of Screening if a single dose was received, or within 12 months of Screening if multiple doses were received. This exclusion does not apply to vaccines (both messenger ribonucleic acid \[mRNA\] and viral vector vaccines).
6. History of gene therapy or cell transplantation, or any experimental brain surgery.
7. Current obstructive hydrocephalus.
8. Known brain or spinal disease or previous spinal surgery that would interfere with the lumbar puncture (LP) process, CSF circulation, or safety assessment.
9. Hospitalization for any major medical or surgical procedure involving general anesthesia within 12 weeks prior to Screening or planned during the study.
10. Have any other conditions, which, in the opinion of the Investigator, would make the participant unsuitable for inclusion, or could interfere with the participant participating in or completing the study.

Where it's running

  • Ionis Investigative Site
    Atlanta, Georgia, United States
    Recruiting
  • Ionis Investigative Site
    Philadelphia, Pennsylvania, United States
    Recruiting
  • Ionis Investigative Site
    Salt Lake City, Utah, United States
    Recruiting
  • Ionis Investigative Site
    Le Kremlin-Bicêtre, France
    Recruiting
  • Ionis Investigative Site
    Göttingen, Germany
    Recruiting
  • Ionis Investigative Site
    Tokyo, Japan
    Recruiting
Show 1 more location
  • Ionis Investigative Site
    Amsterdam, Netherlands
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

  • Characterizing biomarkers and disease progression in Pelizaeus-Merzbacher Disease

    This study is trying to see how certain markers in the body change over time in people with Pelizaeus-Merzbacher Disease to help develop better treatments in the future.

    Recruiting at 7 sites Ionis Pharmaceuticals, Inc. · Atlanta, Georgia and 9 other locations · NCT05659901

  • Long-term observation of rare genetic brain disorders

    This study is tracking how rare genetic brain disorders progress over time to better understand their effects on patients.

    Recruiting University of Pittsburgh · Pittsburgh, Pennsylvania · NCT03333200

  • Collecting data and samples from patients with leukodystrophy

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    Recruiting at 23 sites Children's Hospital of Philadelphia · Los Angeles, California and 22 other locations · NCT03047369

  • Using umbilical cord blood cells to treat inherited metabolic diseases

    This study is testing if a new treatment using special cells from umbilical cord blood can help people with inherited metabolic diseases and early signs of nerve damage feel better when combined with standard cord blood transplants.

    Recruiting Phase 1 Duke University · Durham, North Carolina · NCT02254863

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.