Just one week after announcing
they have begun re-dosing drisapersen in patients with Duchenne muscular dystrophy (DMD) in the United States, Prosensa Holding N.V. has extended its re-dosing program of drisapersen into Europe.
The two sites that will begin re-dosing in the PRO051-02/DMD114673 extension study – a study that was ongoing for almost 4 years prior to dosing being suspended in September 2013 – are located in Belgium and Sweden.
The re-dosing program in Belgium is being led by Dr. Nathalie Goemans, Head of the Neuromuscular Reference Center for Children at the University Hospitals Leuven (UHL) and in Sweden is led by Dr. Mar Tulinius, Professor and Chief Physician at the University of Gothenburg.
In a press release
, Dr. Goemans stated:
"When natural history of the disease suggests that Duchenne muscular dystrophy boys lose between 40-60 meters in their 6MWT per year, the results from this long-running study are very encouraging in terms of walking ability and other measures of muscle function. Boys treated in our clinic are eager to get back onto drisapersen treatment since dosing was stopped last year."
Dr. Giles Campion, Prosensa's Chief Medical Officer added:
"Today's news that Dr. Goemans has been able to resume dosing of boys with Duchenne muscular dystrophy is another step forward towards our goal of making drisapersen available to as many boys as possible in a timely manner. We are pleased that we have been able to accomplish this soon after re-dosing began in the US, and we anticipate Dr. Tulinius' site to resume dosing imminently."
In September, 2013, all dosing in the drisapersen clinical program was placed on hold following the disappointing initial evaluation of the phase 3 study. Subsequent analysis of the data, as well as discussions with the U.S. Food and Drug Administration (FDA), led Prosensa to announce
in June, 2014 that they had received guidance for the FDA on how to best proceed using the existing data.
The company is now ready to start that process and for the first time since last September, boys with Duchenne muscular dystrophy are being tested with the drug drisapersen.
Details of the re-dosing and any future trials by Prosensa are not known at press time but in their June press release, they noted that the FDA suggested at least two additional studies be conducted – a historically controlled trail and a randomized, placebo-controlled trial of another exon-skipping drug with a similar mechanism of action.
About Duchenne Muscular Dystrophy
Duchenne muscular dystrophy is a progressive muscle disorder caused by the lack of functional dystrophin protein. Patients with Duchenne muscular dystrophy lose the ability to walk as early as age 10 and experience life-threatening lung and heart complications in their late teens and twenties.
There are an estimated 35,000 patients with Duchenne in the United States and Europe but the population has many subsets based on mutations of the dystrophin gene.
Both Sarepta’s eteplirsen or Prosensa’s drisaperson should be effective in the same 13% of the Duchenne population who would benefit from exon 51 skipping therapy (i.e., those with mutations near exon 51 of the dystrophin gene) while PTC Therapeutics’ ataluren should be effective in another 13% subset who have nonsense mutations in the dystrophin gene.
All three companies are starting, or have started, phase 3 confirmatory studies.