After over a decade of largely unsuccessful clinical trials, the persistence of gene therapy researchers is finally beginning to pay off. Two weeks ago came news of the remarkable recovery made by Rhys Evans, the UK toddler who underwent gene therapy to treat an inherited immune system disorder.
The scientists at the Institute of Child Health in London who carried out Rhys's pioneering treatment, though obviously delighted with the outcome, were cautious about calling it a cure. Rhys's health will have to be monitored for many years, to ensure his immune system continues to work normally. But the follow-up results of a similar trial, reported in this week's BioNews, indicate that it will.
Two years ago, a team of French scientists reported the successful use of gene therapy to treat two boys affected by X-linked severe combined immune deficiency (X-SCID), the same disorder that affected Rhys Evans. A new study published by the team from the Necker Hospital for Sick Children in Paris reports these that two boys, as well as two other patients, are continuing to live normal, healthy lives. These children could be the first patients to be permanently cured by gene therapy.
Gene therapy, initially hyped as a potential 'wonder-cure' for many genetic disorders, has suffered many setbacks over the years. As in any new field of medicine, researchers have had to overcome many technical stumbling blocks. The main difficulty has been delivering enough copies of the working genes to the cells that need them. Researchers have focussed on immune system disorders because bone marrow is fairly easy to get at, and because it contains white blood stem cells - 'parent' cells that give rise to other immune system cells. The successes of the recent X-SCID trials represent a landmark in gene therapy research, raising hope that new treatments can be developed for a range of other diseases.