The US Food and Drug Administration (FDA) halted 27 gene therapy trials Tuesday following indications that a second child is showing signs of leukemia after treatment for X-linked Severe Combined Immune Deficiency (X-SCID). A group at Great Ormond Street Hospital in the UK will also stop conducting trials as it confers with UK health officials and families of treated children.
Alain Fischer's group at the Necker Children's Hospital in Paris carried out what was largely considered the first unequivocal success in gene therapy. Though at least one researcher has questioned the methods employed by the group, they effectively restored immune function in 10 of 11 patients who would have likely died from X-SCID. Fischer told the FDA last fall and again a month ago that patients were exhibiting leukemia-like symptoms.
The first announcement prompted the FDA to place three SCID trials in the US on clinical hold. Philip...