Gene Therapy Shows 95% Success in Treating ADA-SCID in Children

An innovative gene therapy developed by researchers at UCLA, University College London, and Great Ormond Street Hospital has shown remarkable results in treating children with ADA-SCID, a rare and life-threatening genetic disorder. A long-term study published in the New England Journal of Medicine reveals that the therapy successfully restored and maintained immune system function in 59 out of 62 children affected by this condition. ADA-SCID is caused by mutations in the ADA gene, which is essential for proper immune function. This leads to severe vulnerabilities to infections and a high risk of mortality in early childhood. The experimental treatment involves collecting blood stem cells from the child, which are modified using a lentivirus to introduce a healthy copy of the ADA gene. After the corrected stem cells are reinfused into the patient, they begin to produce healthy immune cells capable of combating infections.

The reconstitution of the immune system takes about six to twelve months, during which patients are monitored closely for recovery and potential complications. The study followed patients treated between 2012 and 2019 and represents the largest and longest follow-up of a gene therapy for ADA-SCID to date, accumulating 474 patient-years of data. Dr. Donald Kohn, a senior author of the study, expressed optimism about the results. He noted the stability of immune function beyond the initial recovery phase and the absence of significant treatment-related complications. Most adverse events reported were mild and associated with standard preparatory procedures rather than the gene therapy itself. Of the three patients who did not achieve the desired immune function, all were able to transition to existing standard-of-care therapies, including bone marrow transplants and enzyme injections.

This highlights the potential of the gene therapy to serve as a viable alternative or complement to traditional treatments, which have limitations and risks. Looking ahead, the research team is working towards obtaining FDA approval for the gene therapy. They are utilizing a cryopreservation method that facilitates the collection and processing of stem cells locally, thereby improving accessibility for patients worldwide. The goal is to have the therapy approved within two to three years, which could significantly impact treatment options for children with ADA-SCID and pave the way for similar gene therapies for other genetic disorders.