Company blocks gene therapy trials

Gene therapy researchers at the Baylor College of Medicine in Houston, Texas, may not get to test a promising new gene therapy delivery system in humans. The team, which recently reported success using the so-called 'gutless' virus in animals, may be stopped from carrying out human trials by the company Merck. The pharmaceutical firm owns the licence on a technique used to produce the viruses.

Merck manufacture the gutless adenoviruses by removing a large chunk of their genome. The adenovirus genome can trigger inflammation in the human body, a process thought to have played a role in the death of 18-year old Jesse Gelsinger last year. But animal experiments with the new gutless adenoviruses showed no significant inflammation, so they might provide a safer alternative, says Arthur Beaudet of Baylor.

Merck says it does not want to be liable for any problems the virus might cause in clinical trials. 'It's the way we handle all products in the early stages of development' said Larry Hirsch, vice-president of public affairs at Merck Research Laboratories. The Baylor team's only alternative is to find a new way to create the gutless virus, which could take years.