A study appearing in Science Translational Medicine puts scientists one step closer to clinical trials to test a gene delivery strategy to improve muscle mass and function in patients with certain degenerative muscle disorders.
Severe weakness of the quadriceps is a defining feature of several neuromuscular disorders. Researchers at Nationwide Children's Hospital have shown that a gene delivery strategy that produces follistatin - a naturally occurring protein that inhibits myostatin, a growth factor expressed specifically in skeletal muscle - directly to the quadriceps of non-human primates results in long-term gene expression with muscle enhancing effects, including larger muscles with greater strength.
Previously, Nationwide Children's researchers demonstrated follistatin's therapeutic potential using rodent models. This more recent study produced similar results in non-human primates, in a translational study to demonstrate efficacy in safety in a species more closely related to humans. Non-human primates that received the injection of the follistatin transgene experienced pronounced and durable increases in muscle size and strength. Muscle growth occurred for 12 weeks after treatment, after which time the growth rates appeared to stabilize and were well tolerated, with no adverse events noted over the course of the 15-month study.
"Our studies indicate that this relatively non-invasive approach could have long-term effects, involve few risks and could potentially be effective in various types of degenerative muscle disorders including multiple forms of muscular dystrophy," said the study's corresponding author, Brian Kaspar, PhD, principal investigator in the Center for Gene Therapy of The Research Institute at Nationwide Children's Hospital.