Single muscle fiber contractile properties in adults with muscular dystrophy treated with MYO-029

Muscle Nerve. 2009 Jan;39(1):3-9. doi: 10.1002/mus.21200.


Myostatin inhibitors are being investigated as treatments for myopathies. We assessed single muscle fiber contractile properties before and after 6 months of study drug in 6 patients with facioscapulohumeral, Becker, and limb-girdle muscular dystrophy. Five of the patients received MYO-029, a myostatin inhibitor, and 1 received placebo. The chemically skinned single muscle fiber preparation was used to measure single fiber force, specific force, maximum unloaded shortening velocity, power, and specific power in type I and IIa fibers from each subject. In 4 of 5 patients who received MYO-029, improvement was seen in single muscle fiber contractile properties; thus, there may be a beneficial effect of myostatin inhibition on muscle physiology at the cellular level. No improvement was seen in the patient who received placebo. This finding may be clinically relevant in spite of the fact that quantitative muscle strength measurements in our patients did not improve. Further studies of myostatin inhibition as a treatment for muscular dystrophy are warranted, and single muscle fiber contractile studies are a useful assay for muscle function at the cellular level.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies / administration & dosage*
  • Antibodies / adverse effects
  • Biological Assay / methods
  • Female
  • Humans
  • Male
  • Middle Aged
  • Muscle Contraction / drug effects*
  • Muscle Contraction / physiology
  • Muscle Fibers, Skeletal / drug effects*
  • Muscle Fibers, Skeletal / metabolism
  • Muscle Strength / drug effects
  • Muscle Strength / physiology
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / physiopathology
  • Muscular Dystrophies / drug therapy*
  • Muscular Dystrophies / metabolism
  • Muscular Dystrophies / physiopathology
  • Myostatin / antagonists & inhibitors*
  • Myostatin / metabolism
  • Placebos
  • Predictive Value of Tests
  • Treatment Outcome


  • Antibodies
  • MSTN protein, human
  • Myostatin
  • Placebos
  • Stamulumab