Antegren ~ New Drug on the Horizon

Dr. Fred Miller,
Chief, Environmental Autoimmunity Group NIEHS,
National Institutes of Health, and TMA medical advisor:

Much interest has been expressed in a new experimental drug called Antegren, a humanized monoclonal antibody, which is one of the first in a new class of potential therapeutics known as alpha 4 integrin inhibitors that are designed to prevent migration of inflammatory cells from blood vessels to sites of inflammation.

Several recent Phase 1-2 clinical studies suggest that Antegren may be useful in the treatment of two autoimmune diseases, multiple sclerosis and Crohn's disease. Antegren binds to cell surface receptors known as alpha-4-beta-1 (VLA-4) and alpha-4-beta-7 integrins. These receptors help white blood cells, particularly T lymphocytes and eosinophils, move from the inside of blood vessels out into the tissues of the body at sites of inflammation, where these cells then participate in the inflammatory process. Blocking these receptors with Antegren prevents the cells from contributing to inflammation by preventing their migration and subsequent activation.

This antibody may be useful in many immune-mediated diseases since most result from inflammation in tissues. Several studies have shown that these receptors (VLA-4) are present on the inflammatory cells in muscles of polymyositis and dermatomyositis patients, and are also likely to be present in juvenile and inclusion body myositis, so there is a possibility that Antegren may be beneficial in treating myositis patients.

At this time, to our knowledge, no myositis patient has been treated with Antegren and there are no studies planned.

Like other immunotherapies, however, there will likely be side-effects from this treatment, including an increased likelihood of infections and delayed wound healing, so only carefully performed research studies in clinical trials will determine the safety and efficacy of such treatments in each disease.

Because other monoclonal antibodies (Enbrel, Remicade and Rituxan), which are already FDA-approved for other diseases, now show some evidence of efficacy in treating myositis and are being studied in myositis trials, it is likely that we will have useful information about the risks and benefits of these drugs in myositis long before such information is available about Antegren.