NCT05127226 · Ionis Pharmaceuticals, Inc.
HALOS: A Safety, Tolerability, Pharmacokinetics and Pharmacodynamics Study of Multiple Ascending Doses of ION582 in Participants With Angelman Syndrome
What this study is about
The purpose of this study is to evaluate the safety and how well patients handle the treatment of ascending doses of ION582 administered intrathecally in participants with Angelman syndrome.
View original scientific description
The purpose of this study is to evaluate the safety and tolerability of ascending doses of ION582 administered intrathecally in participants with Angelman syndrome.
Interventions
DRUG
ION582
ION582 will be administered by IT injection.
Primary outcome measures
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).
Time frame: 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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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. Currently receiving stable standard of care treatments such as, stable doses of anti-epileptic medication, behavioral management medications, sleep medications, gabapentin, cannabidiol, and including special diets, supplements or nutritional support for at least 3 months prior to first dose. 4. Follow good study practice and not participate in the sharing of personal or study information on social media platforms, such as any website or social media site (e.g., Facebook, Instagram, Twitter, YouTube, etc.) until notified that the study is completed. Key
Exclusion criteria
- Has documented molecular AS confirmation of paternal uniparental disomy (UPD) or imprinting defect (ID). 2. Any clin
Where
- San Diego, California
- Aurora, Colorado
- Chicago, Illinois
- Boston, Massachusetts
- Carrboro, North Carolina
- Houston, Texas
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Nov 14, 2025 · Source of record for eligibility and locations