Muscular Dystrophy | Niche & Rare Disease Landscape & Forecast | US/EU5 | 2016
Muscular dystrophies (MDs) are a spectrum of genetic disorders characterized by muscle weakness that in severe disease forms can lead to loss of ambulation and early death. MDs share common histological features such as reduction in muscle fiber size, degeneration, and presence of connective and adipose tissue instead of muscle. Duchenne muscular dystrophy (DMD) is the most common subtype with childhood onset, while myotonic dystrophy is the most common in adults. The unmet need for effective treatments that can meaningfully delay or halt progressive muscle degeneration in DMD, as well as in other severe and moderately severe MDs, is high. Ataluren (PTC Therapeutics’ Translarna) targets a genetically defined subset of DMD patients and has been available in some markets following its 2014 European approval; and eteplirsen (Sarepta’s Exondys 51) was granted accelerated approval in the United States in early 2016 and targets a different group of DMD patients who share a similar genetic mutation at the basis of their disease. Though both drugs target the underlying cause of the disease and thus could potentially modify its course, their efficacy as observed in clinical trials thus far appears modest, and the unmet need for effective disease-modifying therapies that would provide relief to all MD patients remains high.
