Sarepta Therapeutics, headquartered in Cambridge, Mass., exercised its option to buy Myonexus Therapeutics for $165 million. As part of the deal, Sarepta picks up five gene therapy candidates to treat distinct types of limb-girdle muscular dystrophy (LGMD). LGMDs are a group of genetic neuromuscular diseases that have a common set of symptoms, including progressive, debilitating weakness and wasting starting in muscles around the hips and shoulders, which then moves to muscles in the arms and legs. Many LGMD subtypes are seriously life-limiting and often life-ending, including the five programs Sarepta acquired.
The original deal was inked in May 2018, when the two companies agreed to partner to develop Myonexus’ five LGMD gene therapy compounds. Three of those programs are currently in clinical development, with the two at the preclinical stage and ready to move into the clinic. In that agreement, Sarepta has an exclusive option to buy Myonexus, which it has now exercised. All five of the LGMD gene therapies use the AAVrh74 vector, which is the same vector system used in Sarepta’s micro-dystrophin program. This vector is designed to deliver treatment to cardiac and skeletal muscle, including the diaphragm, without inadvertently crossing the blood-brain barrier. This is particularly useful in treating muscular diseases.