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

NCT07782827 | Not Yet Recruiting Phase 3 DMC FDA Drug

• 1 other identifier: ION582-CS3
• Study Type: interventional
• Target: 30
• Locations: 0 countries
• Sites: N/A

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.

Conditions

Angelman Syndrome

Keywords

Paternal Uniparental Disomy; ION582; imprinting defects

Outcome Measures

Primary Outcomes (1)

• 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 1

  Baseline and Week 52

Secondary Outcomes (7)

• Change From Baseline in Bayley-4: Cognition Scale Raw Score Without Caregiver Input

  Baseline and Week 52

• Change From Baseline in Aberrant Behavior Checklist - Second Edition - Community Version (ABC-2-C): Hyperactivity

  Baseline and Week 52

• Change From Baseline in (ABC-2-C): Irritability

  Baseline and Week 52

• Change From Baseline in Vineland Adaptive Behavior Scale-3 (Vineland-3): Receptive Communication Domain Raw Score

  Baseline and Week 52

• Change From Baseline in Vineland-3: Daily Living Skills, Personal Domain Raw Score

  Baseline and Week 52

Study Arms (1)

obudanersen 80 mg

EXPERIMENTAL

Participants in Cohorts 1 and 2 will be administered obudanersen via intrathecal (IT) bolus injection every 12 weeks during the Treatment Evaluation and LTE periods.

Drug: obudanersen

Interventions

obudanersen DRUG

ION582 will be administered by IT injection.

Also known as: ION582

obudanersen 80 mg

Eligibility Criteria

• Age: 2 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Ionis Pharmaceuticals, Inc.: lead

MeSH Terms

Conditions

Angelman Syndrome

Condition Hierarchy (Ancestors)

Movement Disorders; Central Nervous System Diseases; Nervous System Diseases; Abnormalities, Multiple; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Chromosome Disorders; Genetic Diseases, Inborn; Imprinting Disorders

Central Study Contacts

Ionis Pharmaceuticals, Inc.

CONTACT

(844) 373-1141; Champion@clinicaltrialmedia.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 20, 2026
• First Posted: August 24, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): May 1, 2028
• Study Completion (Estimated): May 1, 2031
• Last Updated: August 24, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will share