Gene therapy restores immunity in infants with rare immunodeficiency disease

Wednesday, April 17, 2019

NIH scientists and funding contributed to development of experimental treatment

A small clinical trial has shown that gene therapy can safely correct the immune systems of infants newly diagnosed with a rare, life-threatening inherited disorder in which infection-fighting immune cells do not develop or function normally. Eight infants with the disorder, called X-linked severe combined immunodeficiency (X-SCID), received an experimental gene therapy co-developed by National Institutes of Health scientists. They experienced substantial improvements in immune system function and were growing normally up to two years after treatment. The new approach appears safer and more effective than previously tested gene-therapy strategies for X-SCID.

These interim results from the clinical trial, supported in part by NIH, were published today in The New England Journal of Medicine.

Infants with X-SCID, caused by mutations in the IL2RG gene, are highly susceptible to severe infections. If untreated, the disease is fatal, usually within the first year or two of life. Infants with X-SCID typically are treated with transplants of blood-forming stem cells, ideally from a genetically matched sibling. However, less than 20% of infants with the disease have such a donor. Those without a matched sibling typically receive transplants from a parent or other donor, which are lifesaving, but often only partially restore immunity. These patients require lifelong treatment and may continue to experience complex medical problems, including chronic infections.