Hero: A Study to Evaluate the Safety, Tolerability, and Pharmacokinetics (PK) and Pharmacodynamics (PD) of ION269 in Participants With Down Syndrome (DS) at Risk for Alzheimer's Disease (AD)
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Phase
Phase 1
Status
Terminated
Study type
Interventional
Design
Randomized · Quadruple · Treatment
Enrollment
1actual
Sites
6
Countries
Spain, United States
Every value on this page is a field the sponsor filed with ClinicalTrials.gov, reproduced. Dates are their own estimates, revised as a study runs, unless the registry marks them actual. sources →
Source: ClinicalTrials.gov, retrieved 2026-08-19
Why the sponsor stopped it
Sponsor decision to terminate study early. Decision not based on safety concerns.
As filed on the registry record, in the sponsor's own words.
Dates
each axis at the precision it was filed, with the registry's own basis| Date | Filed | Basis | What it is |
|---|---|---|---|
| Start | 2024-12-20 | actual | When the study began enrolling |
| Primary completion | 2025-12-03 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2025-12-03 | actual | The whole study's end, after follow-up |
| First posted | 2024-11-04 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2026-02-20 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Conditions
- Alzheimer Disease
- Down Syndrome
Intervention
- Drug: ION269
Primary outcomes
what the primary-completion date above is the date OFNumber of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
measured Up to approximately Week 40
Number of Participants With Change from Baseline in Laboratory Assessments
measured Up to approximately Week 40
Number of Participants With Change from Baseline in Cerebrospinal fluid (CSF) Safety Laboratory Assessments
measured Up to approximately Week 40
Number of Participants With Change From Baseline in Vital Signs
measured Up to approximately Week 40
Number of Participants With Change From Baseline in Weight
measured Up to approximately Week 40
Number of Participants With Change From Baseline in Electrocardiogram (ECG)
measured Up to approximately Week 40
Number of Participants With Change From Baseline in Suicide Risk Measured by Columbia Suicide Severity Rating Scale [C-SSRS] Child Version
measured Up to approximately Week 40
Number of Participants With Change From Baseline in Physical and Neurological Examination Findings
measured Up to approximately Week 40
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