Observational Study to Characterize Biomarkers and Disease Progression in Participants With Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome
← catalyst calendarSponsored by Ionis Pharmaceuticals, Inc. (industry) · IONS — their whole pipeline →.
Phase
—
Status
Terminated
Study type
Observational
Enrollment
29actual
Sites
5
Country
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 due to sufficient data collected, the study objectives met and defined unmet need and disease trajectory in males with MECP2 duplication syndrome.
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 | 2023-10-03 | actual | When the study began enrolling |
| Primary completion | 2025-10-07 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2025-10-07 | actual | The whole study's end, after follow-up |
| First posted | 2023-08-28 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2026-04-09 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome
Primary outcomes
what the primary-completion date above is the date OFChange From Baseline in MeCP2 in the CSF
measured Baseline and on Weeks 13, 26, 39, 52
Laboratory biomarkers for MECP2 Duplication
measured Baseline and on Weeks 13, 26, 39, 52
Change From Baseline in MECP2 Duplication Syndrome Severity Scale Across All Domains
measured Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in the Revised Motor Behavioral Assessment
measured Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in the Bayley Scales of Infant and Toddler Development, 3rd Edition
measured Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Vineland Adaptive Behavior Scales 3rd Edition
measured Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Observer Reported Communication Ability Measure
measured Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Quality-of-Life Inventory-Disability Score
measured Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in the Frequency of Seizures
measured Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Global Assessment of Severity of Epilepsy Scale Score
measured Baseline and on Weeks 13, 26, 39, 52, 78, 104
Permalink · IONS's whole pipeline · Catalyst calendar · Every registered study · What changed