By InvitationPhase 2

An Open-Label Extension Study to Evaluate the Long-term Safety and Efficacy of BMN 351 in Participants With Duchenne Muscular Dystrophy

Italy, Netherlands, Spain18 participantsStarted 2026-04

Plain-language summary

This open-label extension study aims to evaluate the long-term safety and tolerability of weekly BMN 351 infusions, as well as to assess the effect of BMN 351 on physical function, in participants with DMD who participated in the 351-201 study.

Who can participate

Age range

4 Years

Sex

MALE

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Participants must have completed 351-201 without permanent discontinuation of the investigational medicinal product (IMP) or withdrawal from the study * Currently receiving treatment with oral corticosteroids, on a stable dose regimen during 351-201, and must remain on a consistent dose regimen throughout 351-202 or 351-203 except for modifications to accommodate changes in weight * Transition to the equivalent dose of vamorolone is permitted in 351-202 where approved in participating countries. * Willing and able to adhere to the study visit schedule and other protocol requirements * Willing to use contraception (sexually mature males) throughout the study and for 90 days after the final dose, if sexually active * Contraceptive use by males should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. * Willing and able to provide written assent (if required by local regulations or the IRB/IEC) after the nature of the study has been explained and prior to performance of any research-related procedure * Willing and able to provide written, signed informed consent as parent or guardian after the nature of the study has been explained and prior to performance of any research-related procedure Exclusion Criteria: * Have known coagulation disorder * Are taking any prohibited medications * any approved exon skipping therapy within 12 weeks prior to baseline or with any gene therapy …

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

To assess the long-term safety and tolerability of BMN 351 in participants with DMD

Timeframe: Through study completion, at least 1 year

Trial details

NCT IDNCT07573631

SponsorBioMarin Pharmaceutical

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2031-12

View on ClinicalTrials.gov More Duchenne Muscular Dystrophy (DMD) trials