Scientists Report Advance in Gene Therapy

Researchers in Pennsylvania said Thursday that they have taken a vital step toward real gene therapy by designing a special gene that can be turned on and off as needed, and by making it work in live animals.

Dr. James Wilson and his colleagues at the University of Pennsylvania School of Medicine said they have specifically tailored a genetic system so that it can be controlled from outside the animal, simply by giving doses of a drug, rapamycin.

The system has already been shown to work for months in mice and monkeys.

“We think it will expand the scope of gene therapy and make it safer, because we have a way to turn it off,” Wilson said in an interview.

Wilson’s report appears today in the journal Science. It’s the first time that an extra gene has been inserted into healthy live animals and been fully regulatable, its activity capable of being turned up, down, on or off.

The goal is to find ways to defeat a large class of inherited diseases, such as sickle-cell anemia and hemophilia, that has resisted treatments and cures because the illnesses are caused by gene mutations that cannot yet be corrected.