Below is a wrap-up of recent research news about the development of therapies for Duchenne, Becker and limb-girdle muscular dystrophies.

Injecting a muscle-repair protein known as WNT7a into the muscles of mice lacking the dystrophin protein and showing a disease resembling Duchenne muscular dystrophy (DMD) significantly increased muscle strength and the size of muscle fibers, leading scientists to conclude that it could be developed into a treatment for DMD and the related disorder

Eteplirsen, an exon-skipping drug in development by Sarepta Therapeutics to treat Duchenne muscular dystrophy (DMD) caused by specific mutations in the dystrophin gene, continues to show benefit at 62 weeks with respect to the distance walked in six minutes.

In both October and December 2012, Sarepta Therapeutics announced very encouraging results from a 12-person phase 2b trial of eteplirsen, an exon-skipping compound that is a potential treatment for Duchenne muscular dystrophy.

Eteplirsen targets exon 51 of the dystrophin gene and is designed to treat DMD caused by specific dystrophin mutations.

New Jersey biopharmaceutical company PTC Therapeutics has announced that the European Medicines Agency (EMA) has validated a "marketing authorization application" (MAA) seeking conditional approval for ataluren, an investigational new drug for the treatment of Duchenne muscular dystrophy (DMD) or Becker muscular

Biopharmaceutical company Sarepta Therapeutics has announced it will expand the focus of its exon-skipping program for Duchenne muscular dystrophy (DMD) by developing compounds that target exons 45, 50 and 53 of the dystrophin gene, in addition to continuing to develop eteplirsen, which targets ex

The drug tadalafil (Cialis, Adcirca), which dilates blood vessels and is approved to treat erectile dysfunction and pulmonary hypertension, has been found to improve blood flow to exercising forearm muscles in people with Becker muscular dystrophy (BMD). Enhancing blood flow may reduce damage related to muscle contraction, although this has not yet been established.