The Strimvelis treatment for ADA-SCID (adenosine deaminase deficiency, severe combined immunodeficiency) involves removing stem cells from the patient's bone marrow, and altering them to contain a working copy of the faulty gene, before injecting them back into the patient.
'This means that children born with ADA-SCID will now have a better chance of being able to lead as near normal a life as possible, going to school, mixing with friends, free from the constant threat of getting a potentially life-threatening infection,' said Professor Carole Longson, director of the Centre for Health Technology assessment at NICE.
In ADA-SCID, a single gene mutation prevents the development of mature immune cells. Children with the condition are susceptible to multiple infections and without treatment are unlikely to reach school age. It is colloquially called 'bubble boy' syndrome because affected children sometimes have to live in sterile chambers to prevent contact with pathogens.
The standard treatment is a bone-marrow transplant, and this is still the recommended treatment where a good match is available. NICE now recommends that Strimvelis be made available on the NHS in cases where no suitable donor can be found.
Because the treated cells are the patient's own, rejection is not an issue.
The cost of the drug, developed by GlaxoSmithKline, is 594,000 euros (£530,000). However, NICE ruled that it is cost-effective, in part because one dose is expected to last the patient's lifetime.
Currently Strimvelis is only available in the Milan hospital where it was first developed, as the stem cells are too short-lived outside the body to be transported to other medical facilities.