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ION582

Phase 1

Angelman Syndrome | Small molecule | Rare Disease |Ionis Pharmaceuticals, Inc.|Last Updated: Aug 20, 2026

Success Probability

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Market & Valuation

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Trial Design

CONTROLLED
Total Trials1
Total Enrollment71

FDA Designations

No designations recorded

Clinical trial landscape

ION582 · 1 trial · 1 indication

Phase 1 1
NCT05127226HALOS: A Safety, Tolerability, Pharmacokinetics and Pharmacodynamics Study of Multiple Ascending Doses of ION582 in Participants With Angelman SyndromeAngelman Syndrome
ACTIVE NOT_RECRUITING71 Analytics
PHASE1ACTIVE NOT_RECRUITING
HALOS: A Safety, Tolerability, Pharmacokinetics and Pharmacodynamics Study of Multiple Ascending Doses of ION582 in Participants With Angelman Syndrome
Angelman SyndromeUnlock trial analytics

Study Endpoints

Primary Endpoints

To evaluate the safety and tolerability of single and multiple doses of ION582 (incidence, severity, and dose-relationship of adverse effects and changes in the laboratory parameters).
Part 1: Up to Week 45; Part 2: Up to Week 81

The safety and tolerability of ION582 will be assessed by determining the incidence, severity, and dose relationship of adverse effects and changes in the laboratory parameters by dose.

Secondary Endpoints

Maximum Observed Plasma Concentration (Cmax) of ION582
Part 1: Up to Week 45; Part 2: Up to Week 81
Time to Reach Maximal Plasma Concentration (Tmax) of ION582
Part 1: Up to Week 45; Part 2: Up to Week 81
Plasma Elimination Half-Life (t1/2λz) of ION582
Part 1: Up to Week 45; Part 2: Up to Week 81
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Study Design & Arms

AllocationNON_RANDOMIZED
MaskingNONE
ModelSEQUENTIAL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
Part 1 MAD: Cohort AEXPERIMENTALION582 will be administered as IT injection over a period of 13 weeks, with a minimum of approximately 4 weeks between each dose administration.
Part 1 MAD: Cohort BEXPERIMENTALION582 will be administered as IT injection over a period of 13 weeks, with a minimum of approximately 4 weeks between each dose administration.
Part 1 MAD: Cohort CEXPERIMENTALION582 will be administered as IT injection over a period of 13 weeks, with a minimum of approximately 4 weeks between each dose administration.
Part 1 MAD: Cohort DEXPERIMENTALION582 will be administered as IT injection over a period of 13 weeks, with a minimum of approximately 4 weeks between each dose administration.
Part 1 MAD: Cohort EEXPERIMENTALION582 will be administered as IT injection of over a period of 13 weeks, with a minimum of approximately 4 weeks between each dose administration.
Part 1 MAD: Cohort FEXPERIMENTALION582 will be administered as IT injection over a period of 13 weeks, with a minimum of approximately 12 weeks between each dose administration.
Part 2 Group 1EXPERIMENTALION582 will be administered as IT injection of over a period of 49 weeks, with additional dosing intervals.
Part 2 Group 2EXPERIMENTALION582 will be administered as IT injection of over a period of 49 weeks, with additional dosing intervals.
Part 3 Group 1EXPERIMENTALION582 will be administered as IT injection of over a period of 145 weeks, with additional dosing intervals.
Part 3 Group 2EXPERIMENTALION582 will be administered as IT injection of over a period of 145 weeks, with additional dosing intervals.

Interventions

NameTypeDescription
ION582DRUGION582 will be administered by IT injection.
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Eligibility Criteria

Age Range0 Years to 50 Years
SexALL
Healthy VolunteersNo
Study Sites11

Key Inclusion Criteria: 1. Participant has a documented and certified diagnosis of Angelman syndrome (AS) (ubiquitin-protein ligase E3A \[UBE3A\] deletion or UBE3A mutation) 2. Male or female between the ages of 0-50 years of age, with signed informed consent from parent(s) or legal guardian(s) 3. ...

Countries:United StatesAustraliaFranceIsraelItalyUnited Kingdom
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Recent Changes (Last 90 Days)

MEDIUMAug 20, 2026NCT05127226Status: RECRUITING → ACTIVE_NOT_RECRUITING
MEDIUMAug 20, 2026NCT05127226Status: RECRUITING → ACTIVE_NOT_RECRUITING

Frequently asked questions about ION582

What is ION582 used for?

ION582 is an investigational small molecule being developed for the treatment of Angelman Syndrome, a rare genetic disorder. It is currently in Phase 1 clinical development and has not been approved by regulatory authorities. The drug is being studied in the HALOS trial, which is evaluating its safety, tolerability, pharmacokinetics, and pharmacodynamics in participants with Angelman Syndrome.

Who makes ION582?

ION582 is being developed by Ionis Pharmaceuticals, Inc., a biopharmaceutical company traded on NASDAQ under the ticker symbol IONS. The company is conducting clinical trials to evaluate the drug's potential as a treatment for Angelman Syndrome, a rare disease. Ionis is responsible for the research, development, and regulatory activities associated with ION582.

What phase is ION582 in?

ION582 is currently in Phase 1 clinical development. The drug is being studied in the HALOS trial, a Phase 1 study that is active but not recruiting participants. As an investigational drug, ION582 has not yet received regulatory approval and is still undergoing clinical evaluation for safety and efficacy in treating Angelman Syndrome.

What clinical trials is ION582 in?

ION582 is being evaluated in the HALOS trial, registered as NCT05127226. This Phase 1 study is a safety, tolerability, pharmacokinetics, and pharmacodynamics study of multiple ascending doses of ION582 in participants with Angelman Syndrome. The trial is active but not recruiting, with an enrollment of 71 participants across the United States, Australia, France, Israel, Italy, and the United Kingdom.

Is ION582 the same as HALOS?

No, ION582 is not the same as HALOS. HALOS is the name of the clinical trial, registered as NCT05127226, that is studying ION582. The trial is a Phase 1 study evaluating the safety, tolerability, pharmacokinetics, and pharmacodynamics of multiple ascending doses of ION582 in participants with Angelman Syndrome. ION582 is the investigational drug being tested in this trial.