A Phase 1/2 Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of BMN 351 in Participants With Duchenne Muscular Dystrophy

April 7, 2026 updated by: BioMarin Pharmaceutical

A Phase 1/2, Open-Label, Dose Escalation Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Multiple Intravenous Doses of BMN 351 in Participants With Duchenne Muscular Dystrophy

The purpose of this study is to test the safety and tolerability of BMN 351 in participants with Duchenne Muscular Dystrophy (DMD) with a genetic mutation amenable to exon 51 skipping.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is Phase 1/2, open-label, multi-center study consisting of 2 parts to evaluate the safety and tolerability of BMN 351 at escalating doses in participants with Duchenne Muscular Dystrophy (DMD) with genetic mutations amenable to exon 51 skipping.

Participants will be assigned to one of three groups called cohorts (Cohort 1, 2 or 3). Cohort 1 participants are further divided into Cohort 1A and Cohort 1B. In Cohort 1A, 3 participants will receive increasing doses once every 2 weeks with a visit to assess safety measures collected the week after dosing prior to escalating doses of BMN 351. In part 2, the participants in cohort 1A will transition to once weekly dosing. The participants in Cohort 1B, 2, and 3 will initiate low, medium, and high doses of BMN 351 and continue once weekly dosing at that same dose. The study will enroll approximately 18 participants.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
18

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • London, Ontario, Canada, N6A 5W9
        • Recruiting
        • Children's Hospital LHSC
        • Principal Investigator:
          • Craig Campbell, MD
        • Contact:
  • Italy
      • Milan, Italy
        • Recruiting
        • Fondazione Serena ETS - Centro Clinico NeMO Milano
        • Principal Investigator:
          • Valeria Sansone
        • Contact:
      • Rome, Italy
        • Recruiting
        • UOC Fase I - Fondazione Policlinico Universitario A. Gemelli IRCCS - Universita Cattolica del Sacro Cuore
        • Principal Investigator:
          • Marika Pane
        • Contact:
  • Netherlands
      • Leiden, Netherlands, 2333 ZA
        • Recruiting
        • Leids Universitair Medisch Centrum
        • Principal Investigator:
          • Erik Niks
        • Contact:
  • Spain
      • Barcelona, Spain, 08950
        • Recruiting
        • Hospital Sant Joan de Déu
        • Contact:
        • Principal Investigator:
          • Andres Nascimento
      • Seville, Spain, 41013
        • Recruiting
        • Hospital Viamed Santa Angela De la Cruz
        • Contact:
        • Principal Investigator:
          • Marcos Madruga-Garrido
  • Turkey (Türkiye)
      • Istanbul, Turkey (Türkiye)
        • Recruiting
        • Yeditepe University Kosuyolu Hospital
        • Principal Investigator:
          • Haluk Topaloglu, MD, Prof
        • Contact:
  • United Kingdom
      • London, United Kingdom, WC1N 3JH
        • Recruiting
        • Great Ormond Street Hospital NHS Foundation Trust
        • Principal Investigator:
          • Giovanni Baranello
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 4 to 10
  • Diagnosis of Duchenne muscular dystrophy with a specific genetic change amenable to exon 51 skipping
  • Able to walk
  • Not requiring assistance from a ventilator to breathe
  • Currently on consistent doses of steroid treatment for the last 12 weeks

Exclusion Criteria:

  • The participant will have some initial clinical labs and studies to assess baseline level of heart and lung function.
  • Treatment with an exon skipping therapy within 12 weeks prior to the first visit.
  • Any history of treatment with gene therapy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Cohort 3
BMN 351 high dose will be administered once weekly for up to 48 weeks
Drug: BMN 351
Anti-sense Oligonucleotide BMN 351 will be administered intravenously.
Experimental: Cohort 1A
Cohort 1A will consist of both a single ascending dose (SAD) part and a multiple ascending dose (MAD). BMN 351 will be administered once every 2 weeks during the SAD portion of the study for up to 8 weeks and once weekly during the MAD portion for up to 89 weeks.
Drug: BMN 351
Anti-sense Oligonucleotide BMN 351 will be administered intravenously.
Experimental: Cohort 1B
BMN 351 low dose will be administered once weekly for up to 97 weeks
Drug: BMN 351
Anti-sense Oligonucleotide BMN 351 will be administered intravenously.
Experimental: Cohort 2
BMN 351 medium dose will be administered once weekly for up to 73 weeks
Drug: BMN 351
Anti-sense Oligonucleotide BMN 351 will be administered intravenously.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
To evaluate and safety and tolerability of single and multiple doses of BMN 351 (incidence, severity, and dose-relationship of adverse effects and changes in laboratory parameters).
Time Frame: Up to 97 weeks.
The safety and tolerability of BMN 351 will be assessed based on the incidence of adverse and serious adverse events.
Up to 97 weeks.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Pharmacokinetics (PK) concentration of BMN 351 in plasma, urine and muscle approximately every 8 weeks for up to 97 weeks.
Time Frame: Serial measurements pre and post infusion.
Serial measurements of plasma and urine PK predose approximately hourly up to 24 hours post-infusion. Muscle PK will be measured at 13 weeks or 25 weeks only post dosing.
Serial measurements pre and post infusion.

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
To evaluate the effect of BMN 351 on physical function.
Time Frame: Change from baseline at week 25.
Change from baseline on 6 Minute Walk Test (6MWT).
Change from baseline at week 25.
To evaluate the effect of BMN 351 on physical function.
Time Frame: Change from baseline at week 25.
Change from baseline on North Star Ambulatory Assessment (NSAA).
Change from baseline at week 25.
Change from baseline in dystrophin expression measured by Liquid chromatography-mass spectrometry (LC-MS).
Time Frame: Baseline, Week 13 or Week 25
Baseline, Week 13 or Week 25
To evaluate the immune response to BMN 351.
Time Frame: Up to 97 weeks
Anti-BMN 351 antibodies, anti-dystrophin antibodies.
Up to 97 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
BioMarin Pharmaceutical

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 3, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 30, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 26, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 20, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 28, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 7, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 351-201
  • 2023-506737-30-00 (Other Identifier: EU CT)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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