Long-Term Efficacy, Safety, and Pharmacokinetics of Drisapersen in Duchenne Muscular Dystrophy: Results from an Open-Label Extension Study | DuchenneXchange

welcome to DuchenneXchange

- a positively charged Duchenne muscular dystrophy community.
  • join today!
Scientific Articles

Long-Term Efficacy, Safety, and Pharmacokinetics of Drisapersen in Duchenne Muscular Dystrophy: Results from an Open-Label Extension Study

key information

source: PLoS One

year: 2016

authors: Goemans NM, Tulinius M, van den Hauwe M, Kroksmark AK, Buyse G, Wilson RJ, van Deutekom JC, de Kimpe SJ, Lourbakos A, Campion G

summary/abstract:

BACKGROUND:
Drisapersen induces exon 51 skipping during dystrophin pre-mRNA splicing and allows synthesis of partially functional dystrophin in Duchenne muscular dystrophy (DMD) patients with amenable mutations.

METHODS:
This 188-week open-label extension of the dose-escalation study assessed the long-term efficacy, safety, and pharmacokinetics of drisapersen (PRO051/GSK2402968), 6 mg/kg subcutaneously, in 12 DMD subjects. Dosing was once weekly for 72 weeks. All subjects had a planned treatment interruption (weeks 73-80), followed by intermittent dosing (weeks 81-188).

RESULTS:
Subjects received a median (range) total dose of 5.93 (5.10 to 6.02) mg/kg drisapersen. After 177 weeks (last efficacy assessment), median (mean [SD]) six-minute walk distance (6MWD) improved by 8 (-24.5 [161]) meters for the 10 subjects able to complete the 6MWD at baseline (mean age [SD]: 9.5 [1.9] years). These statistics include 2 subjects unable to complete the test at later visits and who scored “zero”. When only the 8 ambulant subjects at week 177 were taken into account, a median (mean [SD]) increase of 64 (33 [121]) meters in 6MWD was observed. Of 7 subjects walking >=330 m at extension baseline, 5 walked farther at week 177. Of 3 subjects walking <330 m, 2 lost ambulation, while 1 declined overall but walked farther at some visits. Over the 188 weeks, the most common adverse events were injection-site reactions, raised urinary α1-microglobulin and proteinuria. Dystrophin expression was detected in all muscle biopsies obtained at week 68 or 72.

CONCLUSION:
Drisapersen was generally well tolerated over 188 weeks. Possible renal effects, thrombocytopenia and injection-site reactions warrant continued monitoring. Improvements in the 6MWD at 12 weeks were sustained after 3.4 years of dosing for most patients. For a small, uncontrolled study, the outcomes are encouraging, as natural history studies would anticipate a decline of over 100 meters over a 3-year period in a comparable cohort.

organisation: University Hospitals Leuven, Belgium; University of Gothenburg, Sweden; Spica Consultants Ltd, UK; BioMarin Pharmaceutical Inc., Netherlands

DOI: 10.1371/journal.pone.0161955

read more full text source