What to Do When Clear Success Comes With an Unclear Risk?

An expert panel, meeting in an emergency session last week, urged the U.S. Food and Drug Administration (FDA) to lift a hold it had placed on three gene therapy trials after a patient treated with gene therapy in France developed cancer (Science, 4 October, p. 34). The panel made the recommendation after concluding that the cancer was almost certainly caused by the gene therapy. For safety reasons, the United States, France, and Germany have suspended clinical trials that use the same gene-transfer technology. But the United Kingdom has not, leaving it up to clinicians and patients to weigh the risks and benefits. FDA's advisers seem to favor the British approach.