Defeat Duchenne Canada expresses our deepest sympathy for the family impacted by the untimely death of another young person with Duchenne muscular dystrophy who died shortly after receiving Sarepta’s ELEVIDYS® (delandistrogene moxeparvovec-rokl). Similar to the teen’s death reported in March 2025 after being treated with ELEVIDYS®, this young person was also non-ambulatory and experienced acute liver failure, leading to death. According to the Roche community letter (see below), these are two deaths among approximately 140 non-ambulatory people who received treatment with ELEVIDYS®. As a result of these deaths, Roche/Sarepta have halted treatment with ELEVIDYS® in people with Duchenne who are non-ambulatory, including stopping their ENVISION Study 303 (NCT05310071) study, which is active in several countries, including Canada.

What is ELEVIDYS®?
ELEVIDYS® is given to people with Duchenne through a single intravenous (IV) infusion. It is a gene therapy that utilizes an adeno-associated viral (AAV) vector to deliver a smaller version of the dystrophin gene, known as a “microdystrophin.” The AAV is used to deliver the healthy gene, allowing a person with Duchenne to create dystrophin with this new healthy gene. Unfortunately, there are side effects called “adverse events” that are known to occur with AAV gene therapies. When someone receives a treatment and experiences a side effect, the doctor who administered the medicine must report this side effect, even if they do not believe the medicine was the cause.

An example of this may be if someone receiving a medicine developed a headache. The doctor would report the headache as a side effect, even if the person has the flu, which could be the cause of the headache. ELEVIDYS® is approved in the United States as a treatment for all people with Duchenne who are at least four years of age with a confirmed mutation in the dystrophin gene, except for those who have any deletion in exon eight and/or exon nine in the Duchenne gene. It is not currently approved in Canada, although Canadians may have participated in the clinical trials.

We have reached out to Sarepta to request additional information for our Canadian community and will update you as soon as we receive more information.

We encourage families participating in the ENVISION study or those with questions about gene therapy or clinical trial participation to consult their neuromuscular care team. Our staff are also available to support you at [email protected].