Developing a brand-new drug takes an enormous amount of time, money and effort. Delays and barriers mean that translation of a promising molecule into an approved drug often takes more than 14 years. It is crucial to advance strategies to reduce this time frame, decrease costs and improve success rates.

Drug repurposing or re-positioning is one such strategy. Many agents, developed or approved for other uses have already been tested in humans, so detailed information is available on their pharmacology, formulation and potential toxicity. Because repurposing/repositioning builds upon previous research and development efforts, new candidate therapies could be ready for clinical trials quickly, speeding their review by Regulatory Authorities and, if approved, their integration into treatment for Duchenne.

Idebenone (Raxone®) is being developed for a number of mitochondrial and neuromuscular indications by the pharmaceutical company Santhera.

Raxone is approved in the EU for the treatment of visual impairment in adolescent and adult patients with Leber's Hereditary Optic Neuropathy (LHON).

In a phase III trial, Raxone significantly delayed the rate of lung function loss in Duchenne patients that were not taking concomitant steroids. Submission of a dossier to obtain marketing authorisation for Duchenne in the US and EU is expected soon.

Another example of a drug that has the potential to be re-purposed for Duchenne is simvastatin. In addition to cholesterol lowering effects, experiments in mice have shown that statins also have potent anti-inflammatory, anti-fibrotic and anti-oxidant effects. In addition, they are already approved for treatment of familial hyperlipidemia in children and a good safety profile has been established. Plans for a clinical trial to assess their effect in Duchenne are ongoing.

Several research groups are investigating other drugs that have the potential to be re-purposed for Duchenne. These include Rimeporide which was initially developed as a treatment for congestive heart failure and is now in phase 1 clinical trials.

The Debiopharm group, in collaboration with Solid Biosciences, are developing Alisporivir as a treatment for Duchenne. Alisporivir has already been tested in more than 1500 patients during development for hepatitis C and has demonstrated an acceptable safety profile. Alisporivir is able to prevent mitochondrial-dependent muscular cell death and has shown promising activity in preclinical models of Duchenne.