Ionis completes pivotal cohort enrollment in REVEAL study
Ionis Pharmaceuticals, Inc. has completed enrollment in the pivotal cohort of the global Phase 3 REVEAL study evaluating obudanersen (ION582) for Angelman syndrome. The study enrolled 136 participants aged 2 to < 18 years, with the adult cohort expected to finish enrollment in Q3 2026. Topline data is anticipated in the second half of 2027.
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Ionis Pharmaceuticals, Inc. has completed enrollment in the pivotal cohort of the global Phase 3 REVEAL study evaluating obudanersen (ION582) for Angelman syndrome. The study targets a potential disease-modifying treatment for a condition with no approved medicines. Topline data from the REVEAL study is anticipated in the second half of 2027.
The pivotal cohort, Cohort 1, enrolled 136 participants aged 2 to < 18 years with a confirmed clinical diagnosis of Angelman syndrome and genetic confirmation of either a UBE3A deletion or UBE3A mutation. The adult cohort, Cohort 2, comprises participants aged 18 to ≤ 50 years and is expected to complete enrollment in the third quarter of 2026.
Study Design and Endpoints
REVEAL (NCT06914609) is a global, randomized, double-blind, controlled Phase 3 study designed to enroll approximately 158 individuals. The study is divided into two cohorts based on age groups.
| Cohort | Age Group | Purpose |
|---|---|---|
| Cohort 1 (Pivotal) | 2 to < 18 years | Evaluation of primary and secondary endpoints |
| Cohort 2 (Adult) | 18 to ≤ 50 years | Additional evaluation |
The primary endpoint is improvement in expressive communication as assessed by the Bayley Scales for Infant and Toddler Development-4 (Bayley-4). Secondary endpoints include overall disease severity, cognition, communication, sleep, motor functioning, and daily living skills.
Regulatory Status and Future Plans
Obudanersen has received Orphan Drug designation from the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA). The FDA has also granted Fast Track and Rare Pediatric designations for the treatment of Angelman syndrome.
Ionis plans to advance obudanersen into the Phase 3 CHAMPION study to evaluate the medicine in people with Angelman syndrome who have uniparental disomy (UPD) or imprinting defect (ID) genotypes. The CHAMPION study is on track to initiate before the end of 2026.
How will the interim data from the adult cohort influence the regulatory strategy ahead of the 2027 topline results?
What potential market share could obudanersen capture if it becomes the first FDA-approved treatment for Angelman syndrome?
How might the success of the CHAMPION study expand the addressable patient population for obudanersen?
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