Gene therapy may someday block cocaine addiction

Within two years, cocaine addicts desperate to kick the habit could take part in a pioneering trial of a gene therapy that gives them extra copies of a gene primed to mop up the drug. The therapy will be combined with a new vaccine that stops cocaine affecting the brain. The idea is that if you get no kick from the drug, you'll be less likely to get hooked again if you relapse.

The gene in question makes a fast-acting version of butyrylcholinesterase, a natural human enzyme which destroys cocaine. Giving multiple copies of it to addicts would prevent them getting a high from the drug while they try to quit.

The therapy should work if experiments in rats are anything to go by – treated rats didn't indulge in cocaine-seeking activity for up to a year.