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• Posted October 16, 2025

Gene Therapy Provides Lasting Cure For 'Bubble Boy' Children

Eliana Nachem is taking a brave step once unthinkable for the 11-year-old girl — she’s starting sixth grade, with dreams of becoming an artist.

As a baby, Eliana lived in complete medical isolation, after her 2014 diagnosis at 3 months of age with ADA-SCID, more popularly known as “Bubble Boy” disease.

Kids with the rare disorder are born with a broken immune system caused by adenosine deaminase (ADA) deficiency, in which a genetic mutation inhibits production of an enzyme essential for immune function.

For these kids, day-to-day activities like going to school or playing with friends can lead to life-threatening infections, because they have no defense against viruses, bacteria and fungi.

“We had to get rid of our dog and cat, she couldn’t go outside, and I had to stop breastfeeding,” Eliana’s mother, Caroline, recalled. “Formula had to be consumed within an hour or thrown out. Everything that might harbor germs was dangerous to her.”

But an experimental gene therapy cured Eliana’s broken immune system at 10 months old, and she has since thrived — attending school, playing basketball, free from the fear that some stray virus or bacteria could strike her down.

Elania is one of 59 children born with ADA-SCID who have been cured using this gene therapy, which will soon be submitted for U.S. Food and Drug Administration (FDA) approval, researchers reported Oct. 12 in the New England Journal of Medicine.

“These results are what we hoped for when we first began developing this approach,” said senior researcher Dr. Donald Kohn, a professor of microbiology, immunology and molecular genetics at UCLA.

“The durability of immune function, the consistency over time and the continued safety profile are all incredibly encouraging,” Kohn said in a news release.

ADA-SCID (Severe Combined Immunodeficiency) is best known from a 1976 TV movie starring John Travolta, "The Boy in the Plastic Bubble," based on the true story of a boy named David, according to the National Institutes of Health. 

In real life, David lived in isolation for nearly 13 years before his death following an unsuccessful bone marrow transplant to cure his condition.

Without treatment, ADA-SCID is often fatal within the first two years of life, researchers noted.

For the new gene therapy, children’s own blood stem cells are collected and treated with a modified virus that implants a healthy copy of the ADA gene.

The treated stem cells are then infused back into the child, where they start producing healthy immune cells capable of fighting infections. It typically takes six months to a year for the immune system to reach normal levels.

For this paper, researchers reported long-term outcomes of 62 children treated with this gene therapy between 2012 and 2019. It's the largest and longest follow-up of children treated using the therapy, the team said.

Eliana received her corrected cells at UCLA in September 2014. “I remember thinking, she’s born again, and now we just get to watch her grow,” Caroline said.

“Now the biggest thing I have to worry about is her entering middle school and bossing me around,” Caroline said with a laugh.

Overall, the team reported on data representing 474 years of patient follow-up, including five children who received the treatment more than a decade ago. The median follow-up was 7.5 years, meaning half of the patients were followed longer, half for a shorter time.

For the 59 patients successfully treated, immune function has remained stable past their initial recovery period, with no severe complications reported.

“What’s most remarkable is that everything has been completely stable beyond the initial three-to-six-month recovery period,” Kohn said. “Treatment was successful in all but three of the 62 cases, and all of those children were able to return to current standard-of-care therapies.”

Two of the three patients who didn’t benefit from the gene therapy went on to receive bone marrow transplants, and another is receiving ADA enzyme injections and preparing for a transplant, researchers said.

More than half the children treated received a frozen preparation of corrected stem cells, and their results were similar to those who received stem cells that had not been frozen.

This potentially opens the gene therapy to any child with ADA-SCID, no matter where they live, researchers said.

“The freezing approach allows children with ADA-SCID to have their stem cells collected locally, then processed at a manufacturing facility elsewhere and shipped back to a hospital near them,” co-lead researcher Dr. Katelyn Masiuk said. She’s chief scientific officer for Rarity PBC, a public benefit corporation founded by alumni of the Kohn lab.

“This removes the need for patients and their families to travel long distances to specialist centers,” Masiuk said in a news release.

The UCLA team is now working to complete the steps necessary to apply for FDA approval of the gene therapy. Rarity PBC has licensed the gene therapy and is partnering with commercial manufacturers to produce it.

More Information

The National Institutes of Health has more on SCID.

SOURCE: UCLA, news release, Oct. 15, 2025