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Current Pipeline

ASO

Ionis • obudanersen

Ionis Pharmaceuticals is exploring an investigational Antisense Oligonucleotide (ASO) approach for paternal gene activation as a potential treatment for Angelman syndrome.

Discovery & DevPre-clinicalPhase 1Phase 2Phase 3To Patients

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About the Program

A therapeutic approach that uses modified RNA or DNA molecules that bind to the RNA of the UBE3A-ATS (UBE3A antisense transcript).

FAST Pillar: Pillar 2: Turn on Dad’s UBE3A
Investigational Drug Name: ION582
Company Website: Ionis
Drug Name: obudanersen (oh-bud-ah-nersen)

Questions about Clinical Trials?

Schedule a private, 1:1 appointment with Niki Armstrong, a genetic counselor who specializes in Angelman syndrome.

Meet with a Genetic Counselor

Media

Update on the Ionis Development Program for Angelman Syndrome (2025)

Update on Ionis' Angelman Syndrome Reveal Trial (2025)

Ionis’ Program Update of ION582 for Individuals Living with Angelman Syndrome (2024)

An Update on HALOS Clinical Trial in Individuals Living with Angelman Syndrome (2023)

Program News

September 11, 2026

Ionis Pharmaceuticals: A letter to the Angelman syndrome community.

September 2, 2026

Update on CHAMPION, Phase 3 clinical trial of ION582 (obudanersen)

July 6, 2026

Ionis completes enrollment in pivotal cohort of the Phase 3 REVEAL study evaluating obudanersen in Angelman syndrome

December 22, 2025

An Update on the ION582 clinical development program including HALOS, REVEAL, and CHAMPION Trials

September 9, 2025

Ionis Receives Breakthrough Therapy Designation for ION582 in Angelman Syndrome

June 11, 2025

First patient dosed in pivotal Phase 3 REVEAL clinical study of ION582 in Angelman syndrome

April 8, 2025

IONIS REVEAL Phase 3 Clinical Trial Update

November 6, 2024

Ionis Pharmaceuticals releases information on their planned phase 3 clinical trial for Angelman syndrome

July 22, 2024

Ionis announces positive detailed results from the HALOS Study of ION582 in people with Angelman syndrome

May 16, 2024

Ionis announces positive topline results from Phase 1/2a trial of ION582 for Angelman syndrome