Avidity Biosciences said Wednesday morning that an experimental medicine successfully knocked down the gene behind a form of muscular dystrophy being pursued by a fleet of drug companies.
The early-stage study examined patients with facioscapulohumeral muscular dystrophy, or FSHD, who generally experience slowly progressive muscle loss in the face, shoulder blades, arms, or lower legs. Unusual for a genetic disease, the primary driver of the condition is not thought to be a particular mutation. Instead, in FSHD patients, a gene that is usually silenced — present but essentially smothered and kept quiet by the cell — reactivates and damages muscle.
Avidity said its drug, called del-brax, cut levels of that gene, called Dux4, by an average of 53% across eight patients. It is the first trial to show significant reductions in gene expressions for the disease. And Avidity said it also saw improvements in muscle function and reductions in creatine kinase, a sign of muscle damage picked up on blood tests.
