Small European study highlights promise of gene therapy for rare immune disease

Genethon's Fulvio Mavilio

A biotech with deep roots in the European gene therapy field has successfully tested a new approach to creating a personalized gene therapy for a rare disorder of the immune system.

A team of investigators in France and the U.K. gathered blood stem cells from a group of 6 children suffering from Wiskott-Aldrich syndrome, corrected the genetic anomaly with a healthy gene replacement using a lentiviral vehicle developed by France's Genethon--which sponsored the study--and then injected the normal cells back into the patients as chemotherapy was used to suppress the defective cells in the host.

According to the investigators, all signs of eczema and infection were eliminated after therapy while one saw his arthritis disappear and another recovered from a crippling case of vasculitis in the lower limbs. They added, though, that the rate of corrected platelets in the patients varied from case to case.

According to The Guardian, one of the children in the study died, though the death was not linked to treatment. About four children out of every million suffer from this disease, which is currently treated with bone marrow replacements.

Adrian Thrasher, a doctor at Great Ormond Street Hospital in London, noted that this small study "is a very powerful example of how gene therapy can offer highly effective treatment for patients with complex and serious genetic disease. It also excitingly demonstrates the potential for treatment of a large number of other diseases for which existing therapies are either unsatisfactory or unavailable."

Over the last few years studies like this have fueled a renaissance of gene therapy programs on both sides of the Atlantic. A host of startups have been launched in the field, with some of the big outfits like Biogen Idec and Bayer jumping in early to pursue new gene therapies for hemophilia and other rare conditions.

Genethon's scientific director is Fulvio Mavilio, who had been co-director of the San Raffaele-Telethon Institute of Gene Therapy in Milan. Just a couple of months ago Biogen Idec ($BIIB) signed a collaboration with the institute after recruiting gene therapy expert Olivier Danos to start a new unit at the company.

"We are all very happy and encouraged by the results of this study," Mavilio said in a statement. "It is the first time that a gene therapy based on genetically modified stem cells is tested in a multicenter, international clinical trial that shows a reproducible and robust therapeutic effect in different centers and different countries. For very rare diseases such as WAS, multicenter clinical trials are the only effective way of proving the safety and efficacy of gene therapy and having it rapidly approved and made available to all patients. We are following the same approach for other rare and less rare blood diseases."

- here's the release (PDF)
- here's the report from The Guardian