Children suffering from Wiskott-Aldrich syndrome have seen their health improve thanks to gene therapy, developed in France.
Hope in the fight against rare diseases. A gene therapy trial, carried out in France and Great Britain, between 2011 and 2014, enabled seven children to see their state of health improve markedly. The first results of this work still in progress and published in the journal JAMA Tuesday, April 21, look promising.
Researchers from AP-HP / INSERM, Necker Hospital, Genethon Laboratory, University and Great Ormond Street Hospital in London have successfully demonstrated the effectiveness of gene therapy in recovery of the immune system of treated children. Their general health also improved significantly for six of them.
An estimated prevalence of 1: 250,000
Wiskott-Aldrich syndrome is a rare and severe complex immune deficiency. Of genetic origin, since it is linked to the X chromosome, it affects 1 in 250,000 people. This pathology is due to mutations in the genes which code for the WAS protein in hematopoietic cells (responsible for the production of blood cells).
Affecting mainly boys, this disease causes hemorrhages, severe and repeated infections, severe eczema and sometimes even cancer. Until today, the only treatment available is a bone marrow transplant with a compatible donor.
Hope against disease
This study, funded by AFM-Telethon and carried out in Paris and London, was carried out on patients, aged 8 months to 16 years, without compatible donors and severely affected.
The treatment consisted of removing blood stem cells from the patients carrying the genetic anomaly, then correcting them in the Genethon laboratory by introducing the healthy WAS gene using a viral vector.
The corrected cells were then reinjected into the patients, previously treated with chemotherapy in order to eliminate their diseased stem cells as well as the autoimmune cells and make room for the new modified cells. After re-injection, their body began to make the missing protein.
Results: Severe eczema and serious infections resolved in all children. One of the young patients even saw his arthritis go away. Another, who had to use a wheelchair because of vasculitis in his lower limbs (attack of the blood vessels) was able to resume normal physical activity.
Anne Galy, INSERM research director who conducted the study at the Généthon laboratory and interviewed by France Info, recalls that these are “experimental therapies” and that the children “will be followed for many more years”.
Marina Cavazzana and Salima Hacein-Bey-Abina, from Necker Hospital, consider that “the results obtained constitute an important therapeutic advance because they concern a complex pathology which affects almost all blood cells with dramatic clinical consequences. . The effectiveness of the treatment indicates that it is now legitimate to hope to treat other complex genetic diseases ”.
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