Three boys in NSW have become the youngest patients in the world to receive therapy for Duchenne Muscular Dystrophy as part of a world-first international clinical trial for children aged under four.

Duchenne muscular dystrophy (DMD) is a rare and life-limiting genetic condition mostly affecting boys that causes rapid muscle weakness and results in almost all patients needing a wheelchair by 12 years of age.

There is no known cure.

The trial will recruit 10 boys under four years of age worldwide, with patients followed over a period of at least five years to measure the therapy's effectiveness, including three in NSW who are being treated at The Children's Hospital at Westmead.

The DMD clinical trial will use a novel viral vector-based gene replacement therapy to target DMD at its root cause, replacing the faulty or mutated gene with a healthy version in a single-dose infusion.

Current management of DMD involves high-dosed steroids, combined with physical therapy and allied health support but while it can lead to some improvement, it is also associated with difficult side effects and is not a long-term treatment. 

Gene replacement therapy has already shown success in treating other genetic conditions, including spinal muscular atrophy (SMA), a condition causing rapidly progressive muscle weakness and early death in children.

NSW Premier Chris Minns said:

"This new gene therapy represents a beacon of hope for these three young boys and their families."

"I'm very proud that NSW is a part of the world trial for this debilitating disease."

"The Sydney Children's Hospitals Network has the expertise and capability to deliver world-leading paediatric clinical trials like this, which can lead to major clinical improvements for these children."

NSW Health Minister Ryan Park said:

"This new gene therapy could be life-changing for children diagnosed with DMD."

"It's an incredible achievement for NSW and The Children's Hospital at Westmead to be leading this trial and showcasing our expertise in gene therapy on the world stage.

"Duchenne Muscular Dystrophy is the most common and rapidly progressive of all the childhood neuromuscular disorders, affecting 1 in 5,000 boys – so this new gene therapy could benefit other children with the condition."

Dr Michelle Lorentzos, Clinical Trials Medical Lead at The Children's Hospital at Westmead:

"This is the only trial in the world treating boys under four years of age - we think by treating the boys earlier, we may be able to prevent much of the weakness and disability that has already occurred in older patients."

"If successful, this treatment could change the landscape of treatment for boys with DMD by offering a transformative intervention that may enable the boys to continue walking into adulthood and also improve their life expectancy."

Clinical Associate Professor Kristi Jones, Principal Investigator on the trial and Staff Specialist in Clinical Genetics at CHW:

"The fact we have been able to run this trial and are the first site in the world to do so, is a remarkable achievement and the result of many years of hard work."

"This wasn't something we would have been able to achieve on our own and we give our sincere thanks to our supporters, like Save Our Son Duchenne Foundation, who have supported our research and teams from the beginning - their advocacy has been instrumental in making this trial possible."

The DMD clinical trial was enabled by the Kids Advanced Therapeutics Program at SCHN, a program kindly supported by Luminesce Alliance and Sydney Children's Hospitals Foundation which aims to deliver clinical trials of advanced therapeutics and to speed up translation into clinical care.