The European Commission has approved the world's first gene therapy for children. The new treatment — Strimvelis — is designed for children with severe combined immunodeficiency or ADA-SCID.
GlaxoSmithKline (GSK)'s new Strimvelis therapy requires the removal of stem cells from a patient's bone marrow. These stem cells are then genetically fixed in a test tube before reintroducing it to the body.
For the first time, a commercially available treatment was granted approval to use gene-repairing methods to treat a disorder. The successful clinical trials also helped in making Strimvelis available within Europe.
"What we are talking about is ex vivo gene therapy - you pull out the cells, correct them in test tube, and put the cells back. If you want to fix a disease for life, you need to put the gene in the stem cells," said Stanford University scientist and pediatrician Maria-Grazia Roncarolo, who led the trials in Milan.
In the Strimvelis clinical trials, researchers were able to document a 100 percent survival rate among the 18 child patients who were followed up between 2.3 and 13.4 years.
This suggested that the new gene therapy can successfully replace the faulty gene with functioning copies with virtually no side effects.
"I would be hesitant to call it a cure. Although there's no reason to think it won't last," said GSK gene therapy development head Sven Kili.
The results of the clinical trials are published in the journal Blood.
Every year, about 15 patients in Europe are diagnosed with ADA-SCID, which stems from a defective gene inherited from both parents. This faulty gene prevents ADA (adenosine deaminase) protein production, which is needed to create the white blood cells called lymphocytes.
Prior to the new treatment, ADA-SCID cure includes a bone marrow transplant, which is a very risky procedure. Another option would be a life-long enzyme replacement therapy.
ADA-SCID is associated with the X-linked SCID, which has been dubbed as the "bubble boy" disease because a child patient in the United States had to live inside a plastic shield to protect him from bacteria and viruses.
The condition can become fatally dangerous to affected children and can leave babies with virtually no defense mechanism against viruses or bacteria.