Blow to gene therapy trials

Gene therapy trials taking place in France and the US were suspended last week after a boy being treated at the Paris Necker Hospital developed leukaemia-like symptoms following treatment. French public health officials ordered a halt to the trials while they undertook an investigation and the decision was quickly mirrored in the US.

The three-year-old boy who developed the leukaemia-like disease was being treated at the Necker Hospital for X-linked severe combined immunodeficiency disease (X-SCID). In May 2000, the hospital reported successes using gene therapy to treat the disease, a single gene disorder affecting only boys. X-SCID is sometimes known as 'babies in the bubble' syndrome, because the children produce no lymphocytes to fight infections and have to be kept in a sterile environment. In the UK last year, Rhys Evans, another boy with the disease, was successfully treated using gene therapy at Great Ormond Street Hospital in London.

The boy who has developed leukaemia received gene therapy in the first month of his life, and seemed to have responded well to the treatment, having fought off infections that he would previously have been incapable of fighting. But his body began to show leukaemia-like symptoms in August this year.

Dr Alain Fischer, the scientist in charge of the Necker Hospital gene therapy programme, has said he is sure that the trials will not be stopped for good, although modifications to the technique used may be required. US health officials will meet their French counterparts in Paris this week to receive advice. In the UK, the Gene Therapy Advisory Committee (GTAC) has not recommended that trials be stopped, although closer monitoring will take place and a sub-committee will be set up to review all UK studies using a similar type of gene therapy.