← Trials/Trial dossier/NCT06673069
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)
A Phase 1b Study to Assess the Safety, Tolerability, and Pharmacokinetics of ION269 in Adults With Down Syndrome (Hero Study)
Lead sponsor
Asset
ION269
Listed sites
6
Recruiting sites
-
Enrollment
1
actual
Study population
Alzheimer’s disease
Key I/E criteria
•Amyloid biomarker required (PET)•Study partner/caregiver required•MRI contraindications excluded
Primary endpoints
•Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)•Laboratory Assessments•Cerebrospinal fluid (CSF) Safety Laboratory Assessments
Footprint
Where this trial recruits
Site locations as reported to ClinicalTrials.gov. Site count is not enrollment count; per-site enrollment is not available from source.
Identifiers
Registered as
Timeline
Milestones
Assets
Drug assets
Study populations
Who this study enrolls
Eligibility
Who can enroll
Inclusion criteria
1. Has a reliable study partner, that is, a parent, sibling, or caregiver ≥ 21 years of age, who has known the participant for > 6 months (i.e., a reliable and competent individual with a close relationship with the participant) and is capable of providing accurate information about the participant's history, can attend all scheduled study visits and provide feedback regarding the participant's symptoms and performance as described in the protocol, and can comply with all study requirements and activities.
2. Has a diagnosis of Down syndrome and has an intelligence quotient (IQ) ≥ 45.
3. Has evidence of amyloid pathology on amyloid-positron emission tomography (PET) scan.
4. Is assessed as being cognitively stable.
5. Is in good health as evidenced by medical history, physical, and neurological examination, and with no diagnosis of dementia or mild cognitive impairment
Exclusion criteria
1. Has unstable psychiatric illness, including psychosis, or untreated major depression within 90 days before Screening, as determined by the Investigator.
2. Has any unstable medical condition likely to hamper the evaluation of safety and/or efficacy of the Study Drug (e.g., moderate or severe untreated obstructive sleep apnea, medical history of clinically significant B12 or folate deficiency that is currently uncontrolled, clinically significant abnormalities of thyroid function, stroke, or other cerebrovascular conditions), as per Investigator's judgment.
3. Is unable to complete MRI and amyloid/tau-PET procedures or has any contraindications to having a brain MRI (e.g., MRI-incompatible pacemaker, aneurysm clips, artificial heart valves, or other metal foreign body; claustrophobia that cannot be medically managed without requiring general anesthesia).
Note: Other protocol defined inclusion/exclusion criteria may apply.
Endpoints (14)
What's being measured
Protocol endpoints and posted registry outcome measures, grouped into outcome categories. Composite endpoints show their component event types. Standard codes (LOINC, SNOMED CT) are shown where available.
Coverage by outcome category
Amyloid biomarkers
2 endpointsChange From Baseline in Concentration of CSF Soluble Amyloid Precursor Protein Alpha (sAPPα)
Time frame:Baseline (Day 1) and Week 36
change from baseline, improvement
Change From Baseline in Concentration of CSF Soluble Amyloid Precursor Protein Beta (sAPPβ)
Time frame:Baseline (Day 1) and Week 36
change from baseline, improvement
Fluid / digital biomarkers
2 endpointsNumber of Participants With Change from Baseline in Cerebrospinal fluid (CSF) Safety Laboratory Assessments
Time frame:Up to approximately Week 40
change from baseline, improvement
CSF Concentrations of ION269
Time frame:Pre-dose and post-dose at multiple timepoints up to Week 40
concentration, descriptive
Safety / tolerability / PK
6 endpointsNumber of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
Time frame:Up to approximately Week 40
event count, event
Number of Participants With Change From Baseline in Vital Signs
Time frame:Up to approximately Week 40
change from baseline, event
Number of Participants With Change From Baseline in Electrocardiogram (ECG)
Time frame:Up to approximately Week 40
change from baseline, event
Area Under the Plasma Concentration-time Curve (AUC) of ION269 From Time 0 to Time of Last Measurable Concentration
Time frame:Pre-dose and post-dose at multiple timepoints up to Week 40
concentration, descriptive
Maximum Observed Plasma Concentration (Cmax) of ION269
Time frame:Pre-dose and post-dose at multiple timepoints up to Week 40
concentration, descriptive
Time to reach Cmax (Tmax) of ION269
Time frame:Pre-dose and post-dose at multiple timepoints up to Week 40
time to event, event
Other (unclassified)
4 endpointsNumber of Participants With Change from Baseline in Laboratory Assessments
Time frame:Up to approximately Week 40
change from baseline, improvement
Number of Participants With Change From Baseline in Weight
Time frame:Up to approximately Week 40
change from baseline, improvement
Number of Participants With Change From Baseline in Suicide Risk Measured by Columbia Suicide Severity Rating Scale [C-SSRS] Child Version
Time frame:Up to approximately Week 40
change from baseline, improvement
Number of Participants With Change From Baseline in Physical and Neurological Examination Findings
Time frame:Up to approximately Week 40
change from baseline, improvement
Provenance
Sources
Trial facts come from public ClinicalTrials.gov records. Endpoint categories are Delfa's classification of those records, not a ClinicalTrials.gov field. All figures reflect the July 21, 2026 snapshot.