Methyl CpG Binding Protein 2 (MECP2) Duplication SyndromeNCT06014541
Observational Study to Characterize Biomarkers and Disease Progression in Participants With Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome
An observational study of Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome, run by Ionis Pharmaceuticals, Inc. at 5 sites in United States.
Trial summary
The purpose of the study is to prospectively assess longitudinal changes in biomarkers (MECP2, potential biomarkers of target engagement and disease activity) in cerebrospinal fluid (CSF) and blood; characterize longitudinal changes in performance on clinical scales (clinician-reported measures of neurodevelopment and… Read more about this study
- Who is it for?
- Ages 1 month to 65 years, men only
- Conditions the study is for
- Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome
- How many people
- 29 participants
- Where
- 5 sitesUnited States
- Study dates
- 3 Oct 2023to 7 Oct 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 1 month to 65 years
- Men only
- No healthy volunteers
- Child, Adult, Older adult
Study population: Participants who have a diagnosis of MDS with genetic confirmation of MECP2 duplication or triplication will be enrolled into this study.
Who may be able to join
- Participant has a diagnosis of MDS with genetic confirmation of MECP2 duplication (or triplication)
- Participant has a parent or caregiver (CG) ≥ 18 years old capable of providing informed consent (signed and dated), and able to attend all scheduled study visits and provide feedback regarding the participant's symptoms and performance as described in the protocol and be able to comply with all study requirements and activities
- Male ≥ 1 month and ≤ 65 years of age
- No contraindications for lumbar puncture (LP)'s, blood draws, sedation (if necessary) or other study activities
- Medically stable to complete the study and will tolerate sedation or general anesthesia and other study activities
Who cannot join
- Clinically significant abnormalities in medical history (e.g., clinically significant renal, hepatic, or cardiac abnormalities; major surgery within 3 months of screening) or upon physical examination that could potentially impact the NH of MDS
- Unwillingness or inability to comply with study procedures, including follow up, as specified by this protocol, or unwillingness to cooperate fully with the Investigator
- Treatment with an investigational drug, gene therapy, stem cell therapy, biological agent, or device within 30 days of screening, or 5 half-lives of investigational agent, whichever is longer (participants cannot be concurrently enrolled in NH00006 and ION440-CS1).
Trial locations and contacts
5 sites in 1 country.
5 sites in 1 country
United States5 sites
Baylor College of Medicine
Houston, Texas, 77030
Vanderbilt University Medical Center
Nashville, Tennessee, 37203
Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19104
Gillette Children's Specialty Healthcare
Saint Paul, Minnesota, 55101
UCSD - Rady Children's Hospital
San Diego, California, 92123
About this study
Official title: A Prospective and Retrospective Observational/Non-interventional Study to Characterize Biomarkers and Disease Progression in Patients With MECP2 Duplication Syndrome
The purpose of the study is to prospectively assess longitudinal changes in biomarkers (MECP2, potential biomarkers of target engagement and disease activity) in cerebrospinal fluid (CSF) and blood; characterize longitudinal changes in performance on clinical scales (clinician-reported measures of neurodevelopment and functioning) and caregiver-reported outcome assessments (communication, gastrointestinal, social-emotional-adaptive behavioral measures); evaluate longitudinal changes in caregiver-reported health-related quality-of-life measures; and assess the frequency, type, and severity of seizures over time.
Read the detailed description
This is a multi-center, non-randomized, non-interventional prospective and retrospective study in up to 40 participants with MECP2 duplication syndrome (MDS) who can undergo general anesthesia or conscious sedation to collect fluid biomarkers (CSF and blood), undergo electrophysiological assessments (electroencephalogram [EEG], evoked potentials [EP], pupillometry), clinical assessments and caregiver reported outcomes measures, to be used in support of the development of therapies for MDS. The study duration for each participant will be approximately 110 weeks.
- Keywords
- MDS
- Medical subject headings
- Rett Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| MECP2 Duplication Syndrome Disease Participants | Participants with a diagnosis of MDS with genetic confirmation of MECP2 duplication (or triplication) will undergo CSF and blood collection, electrophysiological and clinical assessments, up to Week 104 as a part of prospective study. Each participant's medical and family history data will be collected retrospectively from available medical notes and charts, from birth up to the end of the study (up to 110 weeks). Participants will have an option to participate in an optional sub-study that will capture pre-defined list of activities at home video. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change From Baseline in MeCP2 in the CSF
Measured: Baseline and on Weeks 13, 26, 39, 52
Laboratory biomarkers for MECP2 Duplication
Proteomic analysis of plasma samples to determine biomarkers of disease progression.
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
Secondary outcomes (3)
Change From Baseline in Auditory Evoked Potential
Measured: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Visual Evoked Potentials
Measured: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Perform a retrospective chart review of the participant's medical history and family history to characterize the natural history of MDS
Measured: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Aug 2023
- Study start3 Oct 2023
- Primary completion7 Oct 2025
- Study completion7 Oct 2025
Why it stopped: 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.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Methyl CpG Binding Protein 2 (MECP2) Duplication SyndromeStudies of the same condition, open and under way.
- More trials run by Ionis Pharmaceuticals, Inc.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Other
- Enrolment
- 29 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ionis Pharmaceuticals, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06014541
- Sponsor's protocol ID
- NH00006
- Status last verified
- Apr 2026
- First submitted
- 9 Aug 2023
- Last updated
- 9 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Ionis may share anonymized individual participant data, aggregated clinical data, and other types of data that support the results in this study. Data requests from qualified researchers will be considered once all three of the following criteria are met: (1) 12 months from marketing approval of the study drug in both the United States and European Union; (2) 18 months from conclusion of the study; and (3) 6 months from publication of study article. Access would be via a secure environment and is contingent upon approval of a research proposal and entry into an appropriate data use agreement. Requests to access data can be submitted via the website https://vivli.org/ourmember/ionis/.
Study at a glance
From the registry record, last updated by the sponsor on 9 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective and Retrospective Observational/Non-interventional Study to Characterize Biomarkers and Disease Progression in Patients With MECP2 Duplication Syndrome
- ClinicalTrials.gov ID
- NCT06014541
- Acronym / sponsor ID
- NH00006
- Keywords
- MDS
- Study type
- Observational
- Recruitment status
- TerminatedReason stopped: 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.
- Enrolment
- 29 participants (actual)
- Lead sponsor
- Ionis Pharmaceuticals, Inc.Industry (pharma, biotech, devices)
- Study start
- 3 Oct 2023 (actual)
- Primary completion
- 7 Oct 2025 (actual)
- Study completion
- 7 Oct 2025 (actual)
- First posted
- 28 Aug 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the study is to prospectively assess longitudinal changes in biomarkers (MECP2, potential biomarkers of target engagement and disease activity) in cerebrospinal fluid (CSF) and blood; characterize longitudinal changes in performance on clinical scales (clinician-reported measures of neurodevelopment and functioning) and caregiver-reported outcome assessments (communication, gastrointestinal, social-emotional-adaptive behavioral measures); evaluate longitudinal changes in caregiver-reported health-related quality-of-life measures; and assess the frequency, type, and severity of seizures over time.
Detailed description
This is a multi-center, non-randomized, non-interventional prospective and retrospective study in up to 40 participants with MECP2 duplication syndrome (MDS) who can undergo general anesthesia or conscious sedation to collect fluid biomarkers (CSF and blood), undergo electrophysiological assessments (electroencephalogram [EEG], evoked potentials [EP], pupillometry), clinical assessments and caregiver reported outcomes measures, to be used in support of the development of therapies for MDS. The study duration for each participant will be approximately 110 weeks.
Study design
- Observational model
- Cohort
- Time perspective
- Other
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| MECP2 Duplication Syndrome Disease Participants | – | –Participants with a diagnosis of MDS with genetic confirmation of MECP2 duplication (or triplication) will undergo CSF and blood collection, electrophysiological and clinical assessments, up to Week 104 as a part of prospective study. Each participant's medical and family history data will be collected retrospectively from available medical notes and charts, from birth up to the end of the study (up to 110 weeks). Participants will have an option to participate in an optional sub-study that will capture pre-defined list of activities at home video. |
Who may qualify
- Ages
- 1 month to 65 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Participants who have a diagnosis of MDS with genetic confirmation of MECP2 duplication or triplication will be enrolled into this study.
Key inclusion criteria (5 listed)
- Participant has a diagnosis of MDS with genetic confirmation of MECP2 duplication (or triplication)
- Participant has a parent or caregiver (CG) ≥ 18 years old capable of providing informed consent (signed and dated), and able to attend all scheduled study visits and provide feedback regarding the participant's symptoms and performance as described in the protocol and be able to comply with all study requirements and activities
- Male ≥ 1 month and ≤ 65 years of age
- No contraindications for lumbar puncture (LP)'s, blood draws, sedation (if necessary) or other study activities
- Medically stable to complete the study and will tolerate sedation or general anesthesia and other study activities
Key exclusion criteria (3 listed)
- Clinically significant abnormalities in medical history (e.g., clinically significant renal, hepatic, or cardiac abnormalities; major surgery within 3 months of screening) or upon physical examination that could potentially impact the NH of MDS
- Unwillingness or inability to comply with study procedures, including follow up, as specified by this protocol, or unwillingness to cooperate fully with the Investigator
- Treatment with an investigational drug, gene therapy, stem cell therapy, biological agent, or device within 30 days of screening, or 5 half-lives of investigational agent, whichever is longer (participants cannot be concurrently enrolled in NH00006 and ION440-CS1).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change From Baseline in MeCP2 in the CSF
Time frame: Baseline and on Weeks 13, 26, 39, 52
Laboratory biomarkers for MECP2 Duplication
Time frame: Baseline and on Weeks 13, 26, 39, 52
Proteomic analysis of plasma samples to determine biomarkers of disease progression.
Change From Baseline in MECP2 Duplication Syndrome Severity Scale Across All Domains
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in the Revised Motor Behavioral Assessment
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in the Bayley Scales of Infant and Toddler Development, 3rd Edition
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Vineland Adaptive Behavior Scales 3rd Edition
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Observer Reported Communication Ability Measure
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Quality-of-Life Inventory-Disability Score
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in the Frequency of Seizures
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Global Assessment of Severity of Epilepsy Scale Score
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
3 secondary outcomes
Change From Baseline in Auditory Evoked Potential
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Change From Baseline in Visual Evoked Potentials
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Perform a retrospective chart review of the participant's medical history and family history to characterize the natural history of MDS
Time frame: Baseline and on Weeks 13, 26, 39, 52, 78, 104
Results and safety
The study was stopped early (reason given: 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.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Apr 2026.
- Individual participant dataSharing planned: Yes. Ionis may share anonymized individual participant data, aggregated clinical data, and other types of data that support the results in this study. Data requests from qualified researchers will be considered once all three of the following criteria are met: (1) 12 months from marketing approval of the study drug in both the United States and European Union; (2) 18 months from conclusion of the study; and (3) 6 months from publication of study article. Access would be via a secure environment and is contingent upon approval of a research proposal and entry into an appropriate data use agreement. Requests to access data can be submitted via the website https://vivli.org/ourmember/ionis/.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome, run by Ionis Pharmaceuticals, Inc. at 5 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 9 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: 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.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change From Baseline in MeCP2 in the CSF (time frame: Baseline and on Weeks 13, 26, 39, 52). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Apr 2026.