Sheffield family plead for help after drug trial for boy, 11, is abruptly stopped

The family of a boy with a rare form of childhood dementia said he had been given “a death sentence” after his treatment was stopped over a failed readmission deal.

Harley Bond, 11, was diagnosed seven years ago with Sanfilippo syndrome, which gradually limits a child's ability to walk, talk and eat.

Harley isn't expected to live beyond 14 years old, but his parents and doctors say his decline has halted since he enrolled in a groundbreaking clinical trial in 2019.

The boy from Sheffield had lost the ability to recognize his parents and no longer said 'mum' and 'dad' before treatment.

But he has since learned to talk again and has spent the past four years as a “healthy, happy boy” who loves trampolining, Toy Story and playing with his three-year-old brother Arlo, his father Wayne said.

However, the world-leading clinical trial treating Harley and fourteen other children was abruptly halted last month. A deal to acquire US-based drugmaker Allievex fell through and the company ran out of cash.

In a letter seen by the Guardian, Allievex told doctors at Great Ormond Street Children's Hospital (GOSH) in London, where two children received the treatment, that “all clinical activity must cease without delay”.

Harley's parents say he is “living proof” that the drug works and have asked for the trial to be resumed. Photo: Christopher Thomond/The Guardian

The company said it had not been able to raise enough money to support a new study, adding: “Know that this is a heartbreaking time for all Allievex employees and shareholders, doctors, parents and especially Sanfilippo patients. ”

Wayne said: “We are extremely angry about it. It functions. Harley's living proof. There are 22 other children around the world who are living proof that it works, but now it will be denied so that generations to come will suffer.”

Wayne and his partner, Emma Siddall, 42, are calling for a pharmaceutical company to back Allievex and restart the trial without delay.

“Please don't give my son a death sentence,” he said. “Let him enjoy his life as he has done for the past eleven years. Don't take this opportunity away from Harley and all the other children who benefit from it.

“It really works. The doctors know it works. The nurses know it works. It's heartbreaking to know that we're basically stranded.”

Many other trials of treatments for Sanfilippo syndrome have failed, but this breakthrough drug, tralesinidase alfa, has shown promising results in clinical trials. It works by releasing a small amount of enzyme in the brain that is missing in children with the condition.

Industry experts said the trial's failure is in large part due to the challenging economic environment for manufacturing drugs for rare diseases, which come at a high cost about five times as much than treatments for more common conditions.

Harley jumps on a trampoline
Doctors at Great Ormond Street Children's Hospital were told by Allievex that the drug trial would stop. Photo: Christopher Thomond/The Guardian

Tom Mathers, CEO of Allievex, said: “The hardest decision I have ever had to make was stopping our ongoing treatment of children with this devastating disease. It is very frustrating because we have a treatment that we know works and has tremendous benefits for the children and their families.”

Mathers said “regulatory uncertainty” in the US and Europe meant it was “impossible” to raise enough money to develop treatments for rare diseases. Allievex needs to raise $70 million to complete the next phase of clinical trial and manufacturing work, he said.

Bob Stevens, chief executive of the MPS Society, which represents young people with Sanfilippo syndrome and other conditions, said children were being “robbed of their future” because of systemic deficiencies in the way programs to treat rare diseases are funded.

“I find it very difficult to live with the fact that we have given a young child a treatment that undoubtedly works and now he no longer has access to it,” he said. “It is a tragic situation that should not have arisen, but is the result of several parts of the system not working.”

A spokesperson for Great Ormond Street said: “We have been caring for Harley and his family at GOSH for many years and have seen the benefit of this investigational treatment for him and other patients.

“We know how impossibly difficult this situation is for everyone involved and our efforts are now focused on supporting Harley and his family.

“Our teams will continue to work closely with them, and others at GOSH, who have been affected by this news, as we explore options and support them in their next steps.”