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

Lucas (3), Hunter (4), and Ollie (3) were all diagnosed with Duchenne muscular dystrophy before their third birthdays. The rare and life-limiting genetic condition affects 1 in 5,000 boys and causes rapid muscle weakness, resulting in almost all children needing a wheelchair by 12 years of age.

Current management involves high-dosed steroids, combined with physical therapy and allied health support, but there is no long-term effective treatment and no known cure.

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

The trial will recruit a total of 10 boys worldwide, with patients followed over a period of at least five years to measure the therapy’s effectiveness.

Dr Michelle Lorentzos, Clinical Trials Medical Lead at The Children’s Hospital at Westmead (CHW), said the trial is hoped to show early intervention can change the clinical trajectory for boys with DMD.

“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,” Dr Lorentzos said.

“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.”

Three-year-old Lucas was the first patient in the world to be dosed in the clinical trial. His mum, Sam, said it was a big decision but they are grateful to have the option of a potential treatment for their son.

“When we found out Lucas was the first, we were nervous but we are so proud of him. We are taking each day as it comes but hope this is an opportunity for a better life for Lucas and one day, leads to a cure for this condition,” Sam said.

Clinical Associate Professor Kristi Jones, Principal Investigator on the trial and Staff Specialist in Clinical Genetics at CHW, said the trial is an incredible achievement for the team.

“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,” A/Prof Jones said.

“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 teams and helped fund our research from the beginning. Their advocacy has been instrumental in making this trial possible.”

Maddison’s son, Hunter, who was second to be enrolled in the trial, says she has seen firsthand the difference clinical trials like this can make.

“These trials are so important because it can change lives - I know it has changed mine,” Maddison said.

“When Hunter was diagnosed, I wanted to give him every opportunity to be able to live a life as long as possible, without devices to help him and to run around and do everything a child should be able to do. This trial is helping him to do that.”

The trial is not only set to help children with DMD, but also open up the possibilities for other genetic diseases.

“The impact of this achievement is beyond potential benefits for Duchenne muscular dystrophy. Many of the capabilities utilised in this trial can be directly translated into treatments for these other diseases,” Dr Lorentzos said.

“This means NSW is positioned to be first in line for other clinical trials and gene replacement therapies that stand to help other Australian children living with rare diseases.”

For families like Ollie’s, who was the third dosed, the trial provides a great deal of hope.

“We are excited to be part of this trial and are hopeful for the best outcomes for Ollie but we are also hopeful for all the other families like ours,” Michael, Ollie’s dad, said.

“No child should ever have to suffer the consequences of a disease like DMD so we just hope that science continues moving forward and these incredible teams can continue finding new ways to help all families going through this.”

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.