FDA calls for end to gene therapy experiment; patients administered therapy develop cancer

• The Food and Drug Administration has suspended several U.S. gene therapy experiments after learning that a third child who underwent treatment in France has developed cancer as a result, a development that has cast a pall over the struggling research field.
• That suggests the treatments may carry long-term as well as near-term risks, said scientists who will be discussing the issue at an FDA meeting.
• The events are the latest in a series of setbacks for a field that a decade ago seemed poised to revolutionize medicine by replacing defective genes with healthy ones -- fixing the molecular underpinnings of disease instead of simply treating its symptoms.
• After thousands of efforts, the treatments appear to have cured only about a dozen patients, all of them children in Europe who were born with a severe immune system disorder.
• "We want to continue, but of course there is a safety issue," said Alain Fischer of the Necker Hospital in Paris, leader of the French study.
• The disease, which affects only boys and disables the immune system, was made famous in the 1970s by David Vetter, the Texas "bubble boy," who lived his 12 years in a plastic tent to protect him from everyday infections that for him could prove fatal.
• The experimental alternative involves infusions of mouse viruses engineered to carry the immune system gene that patients lack.
• The FDA does not generally tell the public about clinical trials it has put on hold, and officials declined to say this week what actions they had taken in light of the latest diagnosis.
• The monkey, whose September death has not been previously publicly disclosed, was one of 42 being watched by NIH scientists for delayed effects of gene therapy.