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

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

Status
Not yet recruiting
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07782827
Enrollment
30
Registered
2026-08-24
Start date
2026-09-01
Completion date
2031-05-01
Last updated
2026-08-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Angelman Syndrome

Keywords

Paternal Uniparental Disomy, ION582, imprinting defects

Brief summary

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.

Detailed description

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.

Interventions

ION582 will be administered by IT injection.

Sponsors

Ionis Pharmaceuticals, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
2 Years to 50 Years
Healthy volunteers
No

Inclusion criteria

Key Inclusion Criteria: 1. 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. 2. 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. 3. Medically stable and can undergo sedation and/or general anesthesia without intubation. 4. Male or female between 2 and ≤ 50 years of age, depending on the specific cohort, at the time of the in-clinic Screening visit. 5. 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. 6. 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

1. Participant has a clinical diagnosis of AS with molecular confirmation of a UBE3A deletion or UBE3A mutation. 2. 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. 3. 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. 4. 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. 5. 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/

Design outcomes

Primary

MeasureTime frame
Change From Baseline in Performance on the Expressive Communication Domain Raw Score Without Caregiver Input of the Bayley Scales for Infant and Toddler Development-4 (Bayley-4) in Cohort 1Baseline and Week 52

Secondary

MeasureTime frame
Change From Baseline in Bayley-4: Cognition Scale Raw Score Without Caregiver InputBaseline and Week 52
Change From Baseline in Aberrant Behavior Checklist - Second Edition - Community Version (ABC-2-C): HyperactivityBaseline and Week 52
Change From Baseline in (ABC-2-C): IrritabilityBaseline and Week 52
Change From Baseline in Vineland Adaptive Behavior Scale-3 (Vineland-3): Receptive Communication Domain Raw ScoreBaseline and Week 52
Change From Baseline in Vineland-3: Daily Living Skills, Personal Domain Raw ScoreBaseline and Week 52
Change From Baseline in (Bayley-4): Fine Motor Domain Raw Score Without Caregiver InputBaseline and Week 52
Change From Baseline in Observer-Reported Communication Ability (ORCA): Overall Emerging and Mastery T ScoreBaseline and Week 52

Contacts

CONTACTIonis Pharmaceuticals, Inc.
Champion@clinicaltrialmedia.com(844) 373-1141

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 25, 2026