GlaxoSmithKline plc (GSK) has been granted Breakthrough Therapy designation by the United States Food and Drug Administration (FDA) for drisapersen, which is a new treatment for Duchenne Muscular Dystrophy.

Set up in 2012 as part of the Food and Drug Administration Safety and Innovation Act (FDASIA), the Breakthrough Therapy designation is intended speed-up the development of drugs for life-threatening conditions.

Results from a phase II study showed that men taking drisapersen were able to walk 35m more than those on placebo, with the difference remaining for up to 48 weeks

Duchenne Muscular Dystrophy (DMD) is a rare disease caused by mutations in the dystrophin gene, resulting in the absence or defect of the dystrophin protein.

GSK’s clinical development plan evaluates the effect of drisapersen in ambulant (Phases II and III) and non-ambulant boys (Phase I) with DMD who have dystrophin gene mutations amenable to an exon 51 skip.

Up to 13% of boys with DMD have dystrophin gene mutations/deletions amenable to an exon 51 skip.

GSK is developing drisapersen under an exclusive, worldwide license from the Dutch company, Prosensa Holding BV.