Researchers from the University of California Los Angeles (UCLA; CA, USA) and Great Ormond Street Hospital (GOSH; London, UK) have collaborated to develop a new gene therapy for the treatment of severe combined immunodeficiency due to adenosine deaminase deficiency (ADA-SCID).

The study, published in the New England Journal of Medicine, reports the 2- to 3-year outcomes of 50 children treated in clinical trials at GOSH, UCLA Mattel Children’s Hospital and the National Institutes of Health between 2012 and 2017.

The gene therapy approach used in the study involved the removal of blood-forming stem cells from the patients and the use of a lentivirus-based vector to deliver a functional copy of the ADA gene. Stem cells were then returned to the patients where they could produce healthy immune cells. Some children received cryopreserved cells while others received non-frozen cells.

Of the 50 children involved in the trials, 2–3 years later, 48 displayed no symptoms of the immunodeficiency disorder. Cryopreservation of the stem cells did not appear to affect the outcomes.

“We started gene therapy at GOSH around 20 years ago and now have refined the process to offer a potential cure for children born with this debilitating condition. Over 200 patients with various genetic conditions across the world have now been treated with this type of gene therapy – this is another very significant breakthrough,” explained study author, Adrian Thrasher (GOSH).

In the other two cases, the children have continued with current standard treatments, which generally involves regular injections of ADA enzymes. In one case, the child received a bone marrow transplant.

“If approved in the future, this treatment could be standard for ADA-SCID, and potentially many other genetic conditions, removing the need to find a matched-donor for bone marrow transplant and the toxic side effects often associated with that treatment,” commented co-lead author of the study, Claire Booth (GOSH). “We need and want guidelines to change so we can start offering this potential cure to children and provide it as a first-choice treatment – this research could set those wheels in motion.”

Link:https://www.regmednet.com/gene-therapy-approach-restores-immune-function-to-children-with-rare-immunodeficiency-disorder/