NCT06430385 · Ionis Pharmaceuticals, Inc.
ATTUNE: A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Intrathecally-Administered ION440 in Participants With Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome (MDS)
What this study is about
The primary purpose of this study is to evaluate the safety and how well patients handle the treatment of ION440.
View original scientific description
The primary purpose of this study is to evaluate the safety and tolerability of ION440.
Interventions
DRUG
ION440
ION440 will be administered by intrathecal bolus (ITB) injection.
PROCEDURE
Sham procedure
An LP will be performed with CSF collection but will not be followed by the administration of study treatment by ITB injection.
Primary outcome measures
Part 1: Number of Participants With Treatment-Emergent Adverse Events (TEAEs)
Time frame: Up to approximately 36 weeks
Part 1: Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Time frame: Baseline up to approximately 36 weeks
Part 1: Number of Participants With Clinically Significant Change From Baseline in Physical and Neurological Examination Findings
Time frame: Baseline up to approximately 36 weeks
Part 1: Number of Participants With Clinically Significant Change from Baseline in Laboratory Assessments
Time frame: Baseline up to approximately 36 weeks
Part 1: Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG)
Time frame: Baseline up to approximately 36 weeks
Part 2: Number of Participants With TEAEs
Time frame: Up to approximately 192 weeks
Part 2: Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Time frame: Baseline up to approximately 192 weeks
Part 2: Number of Participants With Clinically Significant Change From Baseline in Physical and Neurological Examination Findings
Time frame: Baseline up to approximately 192 weeks
Part 2: Number of Participants With Clinically Significant Change from Baseline in Laboratory Assessments
Time frame: Baseline up to approximately 192 weeks
Part 2: Number of Participants With Clinically Significant Change From Baseline in ECG
Time frame: Baseline up to approximately 192 weeks
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
- for Part 1: 1. Males age ≥ 2 years to ≤ 65 years old, depending on specific cohort and group, at the time of informed consent. 1. Group A: ≥ 8 to ≤ 65 years old 2. Group B: 2 to 7 years old, inclusive 2. Participant has at least one parent or caregiver ≥ 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 able to comply with all study requirements and activities, 3. Participant has a documented diagnosis of MDS, with genetic confirmation of MECP2 duplication 4. Is currently receiving stable doses of concomitant medications for at least 3 months prior to baseline. If recent changes (\< 3 months stable) in medications, the participant may be allowed per Investigator judgment in consult with Sponsor Medical Monitor. 5. Able to complete all study procedures, measurements and visits and caregiv
Where
- San Diego, California
- Aurora, Colorado
- Baltimore, Maryland
- Boston, Massachusetts
- Saint Paul, Minnesota
- Philadelphia, Pennsylvania
- Nashville, Tennessee
- 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 Mar 24, 2026 · Source of record for eligibility and locations