A breakthrough stem cell therapy developed by British doctors allowed young patients to be cured of a deadly genetic disease. This is a real breakthrough in gene therapy.
Boys with acute Wiskott-Aldrich syndrome, a rare hereditary blood disorder, have been asymptomatic for four years.
Although less than a hundred children in Great Britain suffer from Wiskott-Aldrich syndrome, the novel therapy gives hope to thousands of patients suffering from other hereditary blood diseases, such as sickle cell anemia.
15-year-old Daniel Wheeler from Bristol is one of seven patients who have undergone innovative gene therapy at centers in London and Paris.
Daniel was diagnosed with the disease when he was two years old. From the very beginning, the boy required constant specialist medical care, he was often hospitalized with symptoms of acute eczema and asthma, and his body was unable to cope with the infection. His older brother died of complications from the disease.
In 2011, Daniel underwent gene therapy and has not had any recurrence of his symptoms since then. Doctors believe that the boy was successfully removed from the disease.
“He’s been in the hospital still since he was two,” says Daniel’s mother, Sarah, 50. “But now his skin is healthy and he has no asthma.” The son can finally live normally.
Professor Adrian Thrasher from the pediatric immunology unit of Great Ormond Street Hospital in London, where the treatment was delivered, believes the new therapy offers hope for patients suffering from incurable diseases.
– We are entering a new era, gene therapies are entering the mainstream of medicine, giving hope to patients for whom conventional therapies have not worked or were unavailable to them – says the doctor.
– The results obtained by us prove that the method is effective in the case of patients who in the past had little chance of surviving without a perfectly matched bone marrow donor.
– We also see considerable potential in the treatment of many other diseases for which currently available therapies are ineffective or unavailable.
The treatment involves removing bone marrow stem cells – the ones that make new blood cells – and replacing the damaged part of the genetic code with a healthy gene. After the defective stem cells are replaced, the patient’s body begins to produce healthy blood cells, free from disease.
Seven boys ranging in age from eight months to 15 years of age were selected for the experiment, and for whom the ideal bone marrow donor could not be matched. Without a bone marrow transplant, patients with Wiskott-Aldrich syndrome rarely live beyond the age of 10.
All of the children had severe eczema, recurrent infections, haemorrhages, and autoimmune diseases. In one case, the disease left the child disabled.
Within two years of starting treatment, children who previously spent an average of 25 days in hospital stopped requiring hospitalization altogether. One of the boys, previously confined to a wheelchair, can walk again.
Gene therapy based on genetically modified stem cells was first tested in international clinical trials that confirmed that the same therapeutic effect can be achieved in different centers around the world, says Fulvio Mavilio of Genethon, the biotechnology company that developed the therapy.
The results are published in the Journal of the American Medical Association.