Preliminary results from a trial to test the safety of injecting follistatin genes into the thigh muscles of adults with Becker muscular dystrophy (BMD)or sporadic (nongenetic) inclusion-body myositis (sIBM) suggest that the experimental therapeutic approach is safe in both types of patients, and that it may improve walking ability in BMD. (Efficacy in IBM patients has not yet been evaluated.)
Follistatin is a protein that interferes with the actions of myostatin, a protein known to inhibit muscle growth.
Neurologist, Jerry Mendell, the principal investigator on this study, reported the preliminary findings at the 2013 annual meeting of the Child Neurology Society (CNS), held in Austin, Texas, Oct. 30-Nov. 2.
About the follistatin gene transfer study
The follistatin gene transfer study is being conducted at Nationwide Children's Hospital in Columbus, Ohio, where Mendell directs the Center for Gene Therapy and the Paul D. Wellstone Muscular Dystrophy Clinical Research Center, and where he co-directs the MDA neuromuscular disease clinic.
The trial began after animal studies conducted in the laboratory of Brian Kaspar, a research scientist at Nationwide Children's, showed follistatin has therapeutic potential.
Mendell is a longtime MDA research grantee, but this follistatin gene-transfer trial is being funded by Parent Project Muscular Dystrophy (PPMD) and the Myositis Association.
Enrollment of BMD patients is complete. Men with BMD who were ambulatory and met other study criteria received an injection of follistatin genes encased in delivery vehicles derived from type 1 adeno-associated viruses (AAV1s) into a thigh muscle in both legs.
Preliminary results in BMD encouraging
Two trial participants with BMD have completed one year of evaluations since receiving low-dose follistatin gene injections. One has increased the distance he is able to walk in six minutes (six-minute walk distance, or 6MWD) compared to his baseline 6MWD by 111 meters (364 feet), and the other by 56 meters (184 feet). A third participant with BMD, who has so far been evaluated six months after receiving the low-dose injections, has increased his 6MWD by 13 meters (43 feet).
Mendell also reported that a participant with BMD who received a higher dose of follistatin genes has increased his baseline 6MWD by 54 meters (177 feet) one month after the injections were administered. "We will be continuing to follow him," Mendell said, adding, "I want to stress that this is preliminary data."
There have been no adverse events.
Testing in IBM patients underway
The follistatin gene transfer trial is also designed to include adults with sporadic (nongenetic) inclusion-body myositis (IBM). Mendell noted that three trial participants with IBM received a very low dose of follistatin genes injected into one leg muscle and were evaluated on safety measures alone. IBM-affected participants will now receive doses comparable to those given to participants with BMD. No adverse events have been seen in the IBM patients.
Mendell invites adults with IBM who are able to walk without assistance and want to be screened for possible participation in the follistatin gene-transfer study to email him at Jerry.Mendell@nationwidechildrens.org.
For more information
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About Clinical Trials
A clinical trial is a test, in humans, of an experimental treatment. Although it's possible that benefit may be derived from participating in a clinical trial, it's also possible that no benefit, or even harm, may occur.