For nearly three years, a child with a deadly genetic disease, which left him without functioning B or T cells, has led a relatively normal life. Doctors in France virtually engineered a working immune system for him through gene therapy.1 Early this month, however, researchers revealed that the gene therapy technique used to treat this child's X-linked severe combined immune deficiency (SCID) probably led to a leukemia-like syndrome. The engineered T cells inevitably began proliferating out of control, an event that always loomed as a possibility. The discovery caused the shutdown of similar gene therapy trials.
At an emergency meeting of the US Food and Drug Administration on Oct. 10, however, a panel of experts urged the FDA to resume three recently suspended US trials, saying that the risk of complications appears too low to deprive patients of a technique that has restored immune function in at least eight of ...