Drisapersen Appears Safe in Non-Walking Boys with DMD

Safety and blood levels of GSK's exon-skipping drug were evaluated in boys with Duchenne MD who were no longer walking and had specific dystrophin mutations

Article Highlights:
  • Drisapersen, designed to target exon 51 of the dystrophin gene in boys with Duchenne muscular who have certain dystrophin mutations, reached blood levels approximately proportional to the injected dose after a single injection at two of the three dosage levels tested.
  • There were no serious adverse events reported, although there were non-serious adverse events.
by Margaret Wahl on November 2, 2012 - 5:15pm

Update (Sept. 19, 2013): This story was updated to reflect the availability of a scientific paper detailing the trial results; it was published online Sept. 11, 2013.

The multinational pharmaceutical company GlaxoSmithKline (GSK) has announced promising results for its phase 1 trial of the exon-skipping drug drisapersen in boys with Duchenne muscular dystrophy (DMD) who are no longer walking.

The phase 1 trial was designed to test safety, tolerability and pharmacokinetics (what the body does to the drug) of drisapersen, not to test drug efficacy.

Results showed that drisapersen (formerly GSK2402968) reached blood levels roughly proportional to the injected dose at two of the three dosage levels tested and that adverse events were not serious.

This trial opened in June 2010 at two sites — Columbus, Ohio, and Paris, France. It included 20 boys with DMD who:

  • had specific mutations in the dystrophin gene amenable to treatment by skipping the exon 51 section of this gene; and
  • had been using a wheelchair full time for at least one year but not more than four years.

Trial participants were randomly assigned to receive either a single injection of drisapersen at varying dosage levels or a placebo injection.

GSK announced detailed results of this phase 1 trial on its website at Result Summaries: GSK2402968 on Nov. 2, 2012.

The full results were published online Sept. 11, 2013, in Neuromuscular Disorders.

Blood levels, adverse events analyzed

In summary, the investigators found that:

  • When drisapersen was injected at a dosage level of 3 or 6 milligrams per kilogram of body weight, blood levels of the drug appeared to be approximately proportional to the dosage given. However, when the results for the 9-milligram-per-kilogram group were included, blood levels did not increase proportionally.
  • In the 3-milligram dosage group, all six participants who received drisapersen injections reported non-serious adverse events, with the most frequently reported being injection site discoloration and injection site induration (tissue hardening).
  • In the 6-milligram group, all six participants who received drisapersen injections likewise reported non-serious adverse events, with the most frequently reported being injection site discoloration and injection site induration.
  • In the 9-milligram group, all three people receiving drisapersen injections reported non-serious adverse events, with the most frequently reported being injection site discoloration, injection site inflammation and fever.
  • Two of the five participants who received placebo injections reported non-serious adverse events, with the most frequently reported being injection site discoloration and injection site induration.
  • There were no serious adverse events or fatalities.
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