Landmark study shows gene therapy a successful treatment for some with 'bubble boy' syndrome
TORONTO -- A new landmark study examining treatment for a debilitating genetic disease known colloquially as "bubble boy" syndrome has found that gene therapy may provide a solution.
There are several types of severe combined immunodeficiency due to adenosine deaminase (SCID or ADA-SCID), but “bubble boy syndrome” refers to when affected children must be extra cautious and protected from germs and infections as their immune systems do not function properly.
The study, released in the New England Journal of Medicine on Tuesday, found that 96 per cent of children treated with gene therapy were able to live normally.
The study followed 50 patients, 20 from the U.K. and 30 in the U.S. – including eight patients from Canada who had been referred by specialists to take part of the study south of the border.
One of those eight patients was Etienne Blais from Nepean, Ont., who was born to parents Pierre and Monica in June 2014 and was diagnosed with bubble boy syndrome.
“We were definitely very afraid that if we didn’t take proper precautions to keep him safe and healthy, that he could die,” Pierre Blais told CTV News.
Etienne wasn’t a candidate for the usual treatment for those born with SCID, a bone marrow transplant from a healthy donor to reboot their immune system, as there was no exact match for him.
So the Blais’ decided to enroll their son in the experimental gene therapy treatment study.
“The hope was that it could set us back on the path towards a bit of normalcy,” Blais said. “Gene therapy…was our only option.”
The study, conducted at the University of California, had researchers take stem cells from children with the more severe form of bubble boy syndrome known as ADA-SCID, and then use inactive HIV virus as a vehicle to insert a corrected gene into their stem cells. The altered stem cells were then infused back into the children.
Researchers including Dr. Donald Kohn, a distinguished professor of microbiology immunology and molecular genetics ad the University of California Los Angeles (UCLA), tracked the results in the patients for years before the study was released.
Out of the 50 patients studied, 48 of them “are well from the gene therapy, off antibiotics and leading basically normal, healthy lives,” Kohn told CTV News.
“It’s wonderful, you know…to have something work so well is just so heartening,” he continued, adding that while researchers hesitate to call this a cure, they are “hopeful” that the results from the study will be “lifelong.”
Etienne, now six years old, has a perfectly functioning immune system – no bubble needed.
“He’s getting into skateboarding and scootering, all those things that six year-olds like to do…things that were not possible at first,” Pierre Blais said.
But going through the experimental treatment was tough on the family, Blais said.
“It is scary…there’s not tons of information about the outcomes, there aren’t a lot of people who’ve gone through it who can talk to you or reassure you…it was nerve wracking” he said. “But at the same time there was a lot of hope…because we knew that this was the first step to getting back to normal.”
Dr. Anne Pham Huy, who works at the Children’s Hospital of Eastern Ontario and referred the Blais family to the UCLA gene therapy study, told CTV News that the results are very promising.
“This is a very big deal for the families and patients, but also a big deal for medicine and science in general opening up the possibility of gene therapy for many genetic diseases,” Huy said.
Huy said she is “excited” about the implications of the gene therapy and how far medicine has come over the past decades. “It’s an amazing concept.”
Until recently, gene therapy for SCID has been available through clinical trials such as the one the Blais family took part in. Now pharmaceutical company Orchard Therapeutics Ltd. based out of London, U.K., has stepped in to manage its wider availability – most likely putting a prohibitive price tag on the treatment.
Most gene therapies cost in the range of $500,000 or more.
“Price has been an issue for many of the gene therapies – it’s expensive to produce the cell therapy in this case, so obviously there’s a problem with access” Kohm told CTV News.
But many are willing to pay the price for the chance for their children to live without bone marrow transplants or lifelong medication to stave off infection.
“We are so relieved that the treatment went well,” Pierre Blais said of Etienne’s improvement. “I don’t know where we would be if it hadn’t been for the gene therapy…I just feel incredibly lucky.”