ClinicalTrials.gov record NCT07782827

CHAMPION: A Study to Evaluate the Efficacy and Safety of Obudanersen (ION582) in Children and Adults With Angelman Syndrome (AS)

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Aug 25, 2026

Phase 3 Study of the Efficacy and Safety of ION582 in Children and Adults With Angelman Syndrome Due to Paternal Uniparental Disomy or Imprinting Defects

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 3A later-stage study, usually with more participants, designed to give stronger evidence about how well a treatment works and how safe it is. It often compares the treatment with standard care or a placebo, and results may support an application for approval.
Age2 years old to 50 years old
SexAll
LocationUnited States
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This Phase 3, open-label study gives obudanersen (ION582) by intrathecal (spinal) injection to people with Angelman syndrome caused by paternal UPD or imprinting defects. The single-arm study enrolls two age-based cohorts and includes screening, an approximately 60-week treatment evaluation, a 101-week long-term extension, and an 8-month post-treatment follow-up. The primary outcome is change in expressive communication measured at baseline and Week 52.

What it is studying. The study tests obudanersen (ION582) delivered into the spinal fluid to see its effects on expressive communication in people with Angelman syndrome due to paternal UPD or imprinting defects. It also collects measures of cognition, behavior, adaptive skills, fine motor ability, observer-reported communication, and safety over the treatment and long-term extension periods.

What the researchers hope to learn. Scientific goals are to evaluate the efficacy and safety of obudanersen in people with Angelman syndrome due to paternal UPD or imprinting defects. The primary scientific endpoint is change from baseline in expressive communication (Bayley-4) at Week 52 in the pediatric cohort. Secondary goals include assessing cognition, behavior (ABC-2-C), adaptive skills (Vineland-3), fine motor function, observer-reported communication, and outcomes during the long-term extension.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

The primary purpose of the study is to evaluate efficacy of obudanersen in participants with AS due to uniparental disomy or imprinting defects (UPD/ID) as measured through expressive communication.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • obudanersen

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • Clinical diagnosis of AS with molecular result indicating either paternal UPD of 15q11.2-q13 or ID of the maternal 15q11.2-q13 region, provided by the Investigator and confirmed by either a qualified central vendor or a qualified local geneticist at the site.
  • The participant's caregiver(s)/legally-authorized representative (LAR) must have given written informed consent and any authorizations required by local law and be able and willing to comply with all study requirements.
  • Medically stable and can undergo sedation and/or general anesthesia without intubation.
  • Male or female between 2 and ≤ 50 years of age, depending on the specific cohort, at the time of the in-clinic Screening visit.
  • If applicable, is currently receiving stable doses of concomitant medications typically prescribed for AS, such as anti-epileptic medication, behavioral management medications, sleep medications, gabapentin, cannabidiol, and special diets, supplements, or nutritional support for at least 8 weeks prior to the Baseline visit. If recent changes (< 8 weeks stable) in medications, the participant may be allowed per Investigator judgment if the change is not expected to have an impact on the signs and symptoms of AS.
  • LAR/caregiver(s) agree(s) not to post any of the participant's personal medical data or information related to the study on any website or social media site (e.g., Facebook, Instagram, X, YouTube, TikTok, WhatsApp) from the time of enrollment until they are notified that the study is completed.
  • Key

Exclusion criteria

  • Participant has a clinical diagnosis of AS with molecular confirmation of a UBE3A deletion or UBE3A mutation.
  • Any clinically significant abnormalities in medical history (e.g., major surgery within 3 months of Screening), or on physical examination for which treatment with an antisense oligonucleotide (ASO) would be contraindicated or which, in the opinion of the Investigator, could confound the results of this study.
  • Known brain or spinal disease that would interfere with the lumbar puncture (LP) procedure, cerebrospinal fluid (CSF) circulation, or presence of other factors that would affect the safety of the LP procedure, including tumors or abnormalities by MRI or computed tomography (CT), subarachnoid hemorrhage, suggestion of raised intracranial pressure (ICP) on magnetic resonance imaging (MRI) or ophthalmic examination, Chiari malformation, obstructive hydrocephalus, syringomyelia, tethered spinal cord syndrome, or connective tissue disorders such as Ehlers-Danlos syndrome and Marfan syndrome.
  • Any laboratory abnormalities or any other clinically significant abnormalities that would, as assessed by the Investigator, at Screening or Baseline, render a participant unsuitable for inclusion.
  • Previous treatment with an oligonucleotide (including small interfering ribonucleic acid [siRNA] and ASOs) or gene therapy or gene editing. This exclusion criterion does not apply to approved nucleic acid-based vaccines, including messenger Ribonucleic Acid (mRNA) vaccines, which are allowed.
  • Other inclusion/exclusion criteria may apply

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

This is a Phase 3, open-label, single treatment arm, multi-center study in participants with Angelman syndrome due to paternal uniparental disomy or imprinting defects. The study will consist of 4 periods: a screening period of up to 28 days, an approximate 60-week Treatment Evaluation Period, followed by 101 weeks of Long-Term Extension (LTE) period, and an 8-month Post-Treatment Follow-up Period. There will be two age-based Cohorts enrolled in this study: Cohort 1 (pediatric participants (aged 2 to <18 years old)) and Cohort 2 (adult participants (aged 18 to ≤50 years old). More individuals will be enrolled in Cohort 1 than in Cohort 2.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants begin with a screening visit (up to 28 days) that includes confirmation of the specific genetic cause (paternal UPD or imprinting defect). The study has an approximately 60-week Treatment Evaluation period, a 101-week Long‑Term Extension, and an 8‑month Post‑Treatment Follow‑Up. During the treatment phases participants receive intrathecal (spinal) injections of obudanersen (ION582) every 12 weeks; the record notes participants must be medically able to undergo sedation and/or general anesthesia without intubation. Study visits include developmental and behavior assessments and questionnaires (for example Bayley‑4, Vineland‑3, ABC‑2‑C, and ORCA), with key measurements taken at baseline and Week 52.

How the study is structured. Phase 3, open-label, single-group interventional trial. All participants receive obudanersen 80 mg by intrathecal (spinal) bolus injection every 12 weeks during the Treatment Evaluation and Long-Term Extension periods. The study includes a screening period (up to 28 days), an ~60-week Treatment Evaluation Period, a 101-week Long-Term Extension, and an 8-month Post-Treatment Follow-up. There is no masking and two age-based cohorts (pediatric and adult).

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on Angelman syndrome

Clinical trials11 trials listed for Angelman syndromeEvery trial the registry lists for Angelman syndrome, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in Angelman syndrome researchLatest monthly update: September 2026. Includes: Seizure frequency. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
September 2026 (estimated)
Primary completion
May 2028 (estimated)
Study completion
May 2031 (estimated)
Target enrollment
30 participants (estimated)
Last updated on registry
Sep 28, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Ionis Pharmaceuticals, Inc.

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (1)

  • University of North Carolina at Chapel Hill School of MedicineRecruiting

    Carrboro, North Carolina, 27510 · United States

Terms used on this page · explanations by MedicalUpdates.ai

primary purpose
The main reason an interventional study is being done, for example treatment, prevention, diagnosis, supportive care or basic science.
LAR
A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
written informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
cohort
A group of people who share a characteristic, such as a diagnosis, and are studied together. 'Prospective' means they are followed forward from enrolment; 'retrospective' means existing records are reviewed.
Screening visit
The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
concomitant medications
Other medicines a participant takes during the study. Some must be reported; some are restricted.
Baseline
Measurements taken at the start of the study, before any study treatment, so that later results can be compared with them.
enrollment
The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
contraindicated
A reason a particular test or treatment should not be used for a person, for example a metal implant that rules out an MRI scan.
lumbar puncture
A procedure in which a needle is placed between the bones of the lower back to collect spinal fluid or to give a treatment.
MRI
A scan that uses magnets and radio waves, not X-rays, to make detailed pictures of the inside of the body. Some implants and metal objects mean a person cannot have one.
computed tomography
An X-ray scan that builds detailed cross-section images of the body. 'High-resolution' CT (HRCT) is used to look closely at the lungs.
exclusion criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
Key Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
open-label
No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
treatment arm
One of the groups in a study. Each arm receives a particular intervention, comparator or no intervention, so the groups can be compared.
Follow-up
The period after treatment or enrolment during which participants are observed or contacted, for example to record side effects or outcomes.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this website; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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