Sarepta’s gene therapy shines

Abstract

A small but encouraging study suggests a gene therapy developed by Cambridge, Mass.-based Sarepta Therapeutics could preserve muscles in boys with Duchenne muscular dystrophy. The early look at the therapy’s effectiveness was presented on June 19 at the biotech firm’s inaugural R&D Day. Its stock price soared nearly 40%. People with Duchenne muscular dystrophy, a rare disease that overwhelmingly affects boys, have an error in a section of the gene for a protein called dystrophin, which cushions muscle cells from wear and tear. Without dystrophin, boys with Duchenne often need to use a wheelchair by their teens, and most die by their early 30s. Over the past two decades, companies have tried many approaches to replacing or repairing the missing protein. In 2016, Sarepta gained approval for Exondys 51, an oligonucleotide that patches over exon 51, a deleted stretch of the gene. But Exondys 51 elicits dystrophin production of less