Gene therapy shows 95% success in treating ADA-SCID in children

Researchers at UCLA, working with University College London and Great Ormond Street Hospital, have seen significant success treating children with adenosine deaminase severe combined immunodeficiency (ADA-SCID) using a new gene therapy. In the largest and longest follow-up study of its kind, the experimental treatment restored and maintained immune function in 59 out of 62 children, representing 474 patient-years of data. These findings, published in the New England Journal of Medicine, highlight the therapy's safety and effectiveness while opening doors for future treatments of the rare genetic disorder.

ADA-SCID is a life-threatening condition driven by mutations in the ADA gene, a component vital to the immune system. Without intervention, children born with the disorder face a high risk of infection, which often proves fatal within the first two years of life. While traditional options like bone marrow transplants or enzyme replacements exist, they carry their own limitations and risks. This gene therapy provides a different path, using a more targeted method to restore the body's natural defenses.

The process begins by collecting a child’s blood stem cells and using a lentivirus to insert a healthy copy of the ADA gene. Once these modified cells are reinfused into the patient, they start producing functional immune cells that can fight off infections. This rebuilding of the immune system usually takes between six to twelve months, after which children often see a marked improvement in their overall health and quality of life.

According to the study, the immune function of treated patients remains stable well past the initial recovery phase, and no complications limited the treatment's success. Most side effects were mild and linked to the preparation procedures rather than the therapy itself. This long-term stability suggests that gene therapy could become a standard treatment for ADA-SCID and other similar conditions in the future.

While the research team pursues FDA approval, they are also looking for ways to make the treatment easier to access. Using frozen stem cell preparations has produced results similar to those using fresh cells, a development that allows for local collection and processing. This change could mean families no longer have to travel long distances for care. The team hopes to secure FDA approval within two to three years, a step that would change how ADA-SCID is managed and bring the therapy to more children globally.