About clinical trials

A clinical trial is a test in humans of an experimental medication or therapy. Clinical trials are experiments, not treatments, and participation requires careful consideration.

Although it's possible to benefit from participating in a clinical trial, it's also possible that no benefit — or even harm — may occur. Keep your MDA clinic doctor informed about any clinical trial participation. (Note that MDA has no ability to influence who is chosen to participate in a clinical trial.)

Researchers supported by MDA are studying the underlying mechanisms that cause inflammatory myopathies, the group of diseases to which inclusion-body myositis (IBM) belongs.

One research team studying the mechanisms of muscle destruction in IBM-affected muscle fibers is building on recent observations that two proteins are abnormally elevated in these fibers. One is called myostatin, which limits muscle growth; and the other is called NF kappa B, which is known to play a role in inflammation.

Treatment with drugs that suppress the immune system has been tried in inclusion-body myositis (IBM) but in general hasn’t been effective. Some physicians may try corticosteroids or other medications that alter the immune response if the patient wishes this treatment, but many feel that side effects outweigh any subtle benefits that might occur with these drugs in IBM.

What causes inclusion-body myositis (IBM)?

In most cases, the cause of IBM is unclear. For some reason, the body’s immune system turns against its own muscles and damages muscle tissue in an autoimmune process.

Viruses might be a trigger for autoimmune myositis. People with the HIV virus, which causes AIDS, can develop a myositis, as can people with a virus called HTLV-1. Some myositis cases have followed infection with the Coxsackie B virus.

As with other muscle diseases, a doctor diagnoses inclusion-body myositis (IBM) by considering the individual’s personal history, family medical history and the results of a careful physical examination. This may be followed by some lab tests, perhaps of the electrical activity inside the muscles. Usually, a muscle biopsy is ordered.

Inclusion-body myositis (IBM) primarily affects men, although women can be affected. It occurs mainly in those older than 50.

IBM usually begins with the gradual onset of slowly progressive weakness in the muscles of the wrists and fingers, and those at the front of the thigh (quadriceps). The muscles that lift the front of the foot also may be affected. The weakness may not be the same on both sides of the body.

What is inclusion-body myositis (IBM)?

The first muscles affected in inclusion-body myositis are usually those of the wrists and fingers, and the muscles at the front of the thigh. The muscles that lift the front of the foot also may be affected.