NCT05371613 · Denali Therapeutics Inc.
A Study to Determine the Efficacy and Safety of Tividenofusp Alfa (DNL310) vs Idursulfase in Pediatric and Young Adult Participants With Neuronopathic (nMPS II) or Non-Neuronopathic Mucopolysaccharidosis Type II (nnMPS II)
(COMPASS)
What this study is about
This is a Phase 2/3, multiregional, two-treatment group$1, where neither patients nor doctors know which treatment is given, randomly assigned, active (standard-of-care)-controlled study of the effectiveness and safety of tividenofusp alfa (DNL310), an experimental central nervous system (CNS)-penetrant enzyme-replacement therapy (ERT) for mucopolysaccharidosis type II (MPS II).
View original scientific description
This is a Phase 2/3, multiregional, two-arm, double-blind, randomized, active (standard-of-care)-controlled study of the efficacy and safety of tividenofusp alfa (DNL310), an investigational central nervous system (CNS)-penetrant enzyme-replacement therapy (ERT) for mucopolysaccharidosis type II (MPS II). Participants may also qualify to enter an open-label treatment phase with DNL310 or idursulfase based on pre-specified criteria.
Interventions
DRUG
tividenofusp alfa
Intravenous repeating dose
DRUG
idursulfase
Intravenous repeating dose
Primary outcome measures
Percent change from baseline in cerebrospinal fluid (CSF) heparan sulfate (HS) concentration (Cohort A)
Time frame: 24 weeks
Change from baseline in the Vineland Adaptive Behavior Scale, Third Edition (Vineland-3)(Cohort A)
Time frame: 96 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
- Participants aged ≥2 to \<6 years (Cohort A) or ≥6 to \<26 years (Cohort B)
- Confirmed diagnosis of MPS II (for Cohort A, nMPS II; for Cohort B, nnMPS II)
- Have no history of treatment with enzyme replacement therapy (ERT) OR not have received continuous ERT for 4 months prior to screening OR be on maintenance ERT and have tolerated idursulfase for a minimum of 4 months prior to screening Key
Exclusion criteria
- Have a documented mutation of other genes or genetic diagnosis accounting for developmental delay
- Previously received an iduronate 2-sulfatase (IDS) gene therapy or stem cell therapy
- Received any CNS-targeted MPS ERT within 6 months prior to screening
- Have a contraindication for lumbar punctures and/or magnetic resonance imaging (MRI)
- Participated in any other investigational drug study or used an investigational drug within 60 days prior to screening or intend to receive another investigational drug during the study
Where
- Oakland, California
- Chicago, Illinois
- Hackensack, New Jersey
- Chapel Hill, North Carolina
- Cincinnati, Ohio
- Philadelphia, Pennsylvania
- Houston, Texas
- Salt Lake City, Utah
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 Aug 5, 2025 · Source of record for eligibility and locations