Hope for a Genetic Disease

In June, the FDA expanded its approval of Sarepta Therapeutics’ Elevidys gene therapy for Duchenne muscular dystrophy to all patients ages four and older. The one-time treatment (which costs $3.2 million) bypasses a genetic mutation to slow progression of the rare but devastating disease, an inherited condition in which children, most often boys, progressively lose muscle strength, affecting everything from the ability to walk to eventually breathing on their own. After a narrow, conditional approval for boys age 4 and 5 in 2023, the expanded approval came as a surprise since the treatment’s Phase 3 trial didn’t hit its primary goal of statistically significant improvement on an assessment of how kids move. But the kids did do better on that metric and other secondary measurements showed statistically significant progress, and families and doctors seeking help for the often fatal condition met it with optimism. “I think the approval brings a lot of hope for Duchenne specifically, but also the platform of gene therapy for neuromuscular disease and beyond,” says Sarepta chief scientific officer Louise Rodino-Klapac, who co-invented the therapy. “It's really a pathfinder for many other gene therapies to come.”