The doctor responsible for gene therapy’s greatest setback is sounding a new alarm - MIT Technology Review
►https://www.technologyreview.com/s/610141/the-doctor-responsible-for-gene-therapys-greatest-setback-is-sound
James Wilson of the University of Pennsylvania reported this week that monkeys and pigs given super-high doses of gene therapy died or suffered disturbing behavioral changes.
“What is remarkable is we have not seen it before,” says Wilson. “We were surprised but shouldn’t have been. If you push the dose of anything high enough, you are going to see toxicity.”
The warning comes amidst a scramble by three companies—Sarepta Therapeutics, Pfizer, and Solid Biosciences—to be the first to use the technique to cure muscular dystrophy. That disease strikes young boys, destroys their muscles, and kills them by their 20s.
To attack the disease, researchers replace patients’ damaged copies of a gene called dystrophin by introducing viral particles that carry a correct copy. Reaching the countless muscle cells in a boy’s body requires extremely high doses of these particles—400 trillion or more per pound of body weight.
R. Jude Samulski, who studies viral gene therapy at the University of North Carolina and is involved with Pfizer’s project, says that because Wilson’s viruses were slightly different from those being used in trials, it is not known whether his findings apply to the studies under way.
However, Samulski says the mixture of scientific ambition, technological advances, desperate patients, and potential financial windfalls could be combustible.
“It would be very naïve for our community to assume we won’t have toxic effects,” he says. “People get comfortable, saying, ‘Hey, let’s do it—there is nothing lose.’ Well, it’s out there waiting. But when it’s going to happen, why it’s going to happen—nobody knows.“