Two decades ago, medicine seemed on the cusp of a revolution. Doctors would soon treat diseases at their very roots, inserting "good" genes to replace patients' faulty ones. Gene therapy was a seductively straightforward idea that offered promise for treating everything from cancer to sickle cell disease.
But only now, after overcoming unexpected scientific obstacles and the high-profile death of a teenage patient, is gene therapy racking up some clear-cut successes. Promising studies are sending ripples of excitement through the field. Some researchers are daring to use the word cure.
"Yes, we have endured a few more years of questions about gene therapy: Does it really work? Is it really safe?" said Savio Woo, a professor at Mount Sinai School of Medicine in New York and a past president of the American Society of Gene Therapy. "Now we can show it does work, and it's safe." That doesn't mean that people will be lining up for gene therapy any time soon. No treatments have been approved yet. But researchers are finally pointing to a few inspiring successes, untainted by the kind of tragedy that cast a shadow on the field in the past.
Gene therapy started the year with a bang: Researchers reported in the New England Journal of Medicine that the technique cured eight of 10 children suffering from usually lethal "bubble boy disease," a lack of immunity that leaves children vulnerable to infections. After two to eight years, all the patients were alive, unlike a previous trial. That came on top of an announcement last year that two groups of researchers independently used gene therapy to treat a form of hereditary blindness in a small number of patients, restoring some vision. The evidence, also published in the New England Journal, was presented at a scientific conference in April.
"I've never seen [such] a response. The audience basically burst into applause, sustained applause, cheering even. It was just amazing," said Sam Wadsworth, group vice president of translational research for Genzyme Corp. in Cambridge, which has its own gene therapy program. Two other studies this month add to the momentum. The journal Nature Medicine, reporting on a trial of 74 HIV patients, said gene therapy had modest but promising effects. A study in the journal Human Gene Therapy reported that two patients with rheumatoid arthritis saw a reduction in pain and swelling with gene therapy. Eight-year-old Corey Haas of Hadley, N.Y., received gene therapy for a rare disease called Leber's congenital amaurosis, which was causing him to go blind. His family knew the treatment worked when, soon thereafter, Corey asked his parents when two of his friends changed their hair color. He could finally tell they were blonde, not brunettes.Read full story »