title: Longitudinal effect of eteplirsen versus historical control on ambulation in Duchenne muscular dystrophy.
abstract: OBJECTIVE
  To continue evaluation of the long-term efficacy and safety of eteplirsen, a phosphorodiamidate morpholino oligomer designed to skip DMD exon 51 in patients with Duchenne muscular dystrophy (DMD). Three-year progression of eteplirsen-treated patients was compared to matched historical controls (HC).
  
  
  METHODS
  Ambulatory DMD patients who were ≥7 years old and amenable to exon 51 skipping were randomized to eteplirsen (30/50mg/kg) or placebo for 24 weeks. Thereafter, all received eteplirsen on an open-label basis. The primary functional assessment in this study was the 6-Minute Walk Test (6MWT). Respiratory muscle function was assessed by pulmonary function testing (PFT). Longitudinal natural history data were used for comparative analysis of 6MWT performance at baseline and months 12, 24, and 36. Patients were matched to the eteplirsen group based on age, corticosteroid use, and genotype.
  
  
  RESULTS
  At 36 months, eteplirsen-treated patients (n = 12) demonstrated a statistically significant advantage of 151m (p < 0.01) on 6MWT and experienced a lower incidence of loss of ambulation in comparison to matched HC (n = 13) amenable to exon 51 skipping. PFT results remained relatively stable in eteplirsen-treated patients. Eteplirsen was well tolerated. Analysis of HC confirmed the previously observed change in disease trajectory at age 7 years, and more severe progression was observed in patients with mutations amenable to exon skipping than in those not amenable. The subset of patients amenable to exon 51 skipping showed a more severe disease course than those amenable to any exon skipping.
  
  
  CONCLUSIONS
  Over 3 years of follow-up, eteplirsen-treated patients showed a slower rate of decline in ambulation assessed by 6MWT compared to untreated matched HC.
authors.affiliation: Nationwide Children's Hospital, Columbus, OH.|Department of Pediatrics and Neurology, Ohio State University, Columbus, OH.|Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, Rochester, NY.
authors.forename: Jerry R
authors.initials: JR
authors.lastname: Mendell
authors.affiliation: University Hospitals Leuven, Leuven, Belgium.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Goemans
authors.affiliation: Nationwide Children's Hospital, Columbus, OH.|Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, Rochester, NY.
authors.forename: Linda P
authors.initials: LP
authors.lastname: Lowes
authors.affiliation: Nationwide Children's Hospital, Columbus, OH.|Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, Rochester, NY.
authors.forename: Lindsay N
authors.initials: LN
authors.lastname: Alfano
authors.affiliation: Nationwide Children's Hospital, Columbus, OH.|Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, Rochester, NY.
authors.forename: Katherine
authors.initials: K
authors.lastname: Berry
authors.affiliation: Sarepta Therapeutics, Cambridge, MA.
authors.forename: James
authors.initials: J
authors.lastname: Shao
authors.affiliation: Sarepta Therapeutics, Cambridge, MA.
authors.forename: Edward M
authors.initials: EM
authors.lastname: Kaye
authors.affiliation: Catholic University of Rome, Rome, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Mercuri
mesh_terms: D000293:Adolescent; D017398:Alternative Splicing; D002648:Child; D018450:Disease Progression; D005080:Exercise Test; D005091:Exons; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D051346:Mobility Limitation; D060172:Morpholinos / Q000008:administration & dosage / Q000494:pharmacology*; D020388:Muscular Dystrophy, Duchenne / Q000188:drug therapy* / Q000503:physiopathology; D009841:Oligonucleotides / Q000008:administration & dosage / Q000494:pharmacology*; D017063:Outcome Assessment, Health Care / Q000379:methods*; D016138:Walking / Q000502:physiology*
chemical_list: D060172:Morpholinos; D009841:Oligonucleotides; C000611335:eteplirsen