Dutch biopharmaceutical company Prosensa, developer of the experimental Duchenne muscular dystrophy (DMD) drug drisapersen, says it is moving the compound forward through regulatory agencies in the U.S. and Europe and will resume administering it to a first group of trial participants in the third quarter of 2014.
The company announced these plans in a May 22, 2014, letter to patient groups. In this same communication, Prosensa introduced its new web page Drisapersen Re-Dosing, which will provide updated tracking of information on administration ("re-dosing") of drisapersen in ongoing studies.
Drisapersen is an exon-skipping drug, designed to cause muscle cells to reinterpret flawed instructions for the dystrophin protein and produce short, but functional, dystrophin. Lack of dystrophin protein in muscle cells is the underlying cause of DMD. Drisapersen is given by injection and targets a section of the dystrophin gene called exon 51.
MDA has funded the development of exon skipping for DMD since the 1990s. A current grant to Steve Wilton at Murdoch University in Australia aims to develop exon-skipping drugs for the rarer DMD-causing mutations in the dystrophin gene
Dosing with drisapersen was halted in September 2013, after a large-scale, phase 3 trial of the drug failed to show a difference on tests of walking distance or other motor function between treated and placebo participants.
However, release of additional data since then has yielded more encouraging results, which Prosensa says support the idea that "treating earlier in the disease and treating for a longer duration confers a treatment benefit for boys with DMD."
Several compounds in development; natural history study underway
The May 22 letter from Prosensa also delivers news about the company's additional exon-skipping compounds in development for DMD and its large-scale natural history study, now being conducted to refine understanding of usual disease progression. The letter offers the following updates.
For more information
Families are invited to send questions to Claire Leyten, manager of patient group relations at Prosensa, at firstname.lastname@example.org.