A trial of beta-interferon-1a in inclusion-body myositis (IBM) has failed to find benefit from the drug in this disease. Beta-interferons counteract some of the activities of the immune system, which some experts believe is misguided in IBM.
A recent pilot trial, supported by MDA, found that 30 micrograms of beta-interferon-1a, given by intramuscular injection once a week, was safe and well tolerated by patients with IBM, but no benefit was detected.
This new trial, with results published in the Aug. 24 issue of Neurology, aimed to see whether 60 micrograms per week for six months would improve muscle strength or mass (bulk) in IBM. This dose was well tolerated, but no differences in muscle strength or mass were observed between the placebo (inactive substance) and interferon-treated groups in this higher-dose study.
The research team notes that it may be necessary to conduct trials that are at least a year in length to detect modest therapeutic responses in this slowly progressive muscle disease. The team included Rabi Tawil (lead investigator) and Charles Thornton, MDA clinic co-directors at the University of Rochester (N.Y.) Medical Center; and Jerry Mendell and John Kissel, MDA clinic co-directors at Ohio State University Hospital in Columbus.
“The results of our studies do not show any trend that would justify going on to larger and longer studies with this agent,” Tawil says. “Other investigators within our Muscle Study Group are interested in trying other, newer immunomodulators [agents that modify the immune system] in IBM, and plans for funding such studies are in progress.”