Interferons

Interferons are proteins that are found naturally in the body. They are part of the immune system and normally help your body respond to infection. There are three types of natural interferons in the body: alpha, beta and gamma. The use of interferon for medical treatment became available when techniques were developed for producing large quantities of them.

Interferon alpha is used in the treatment of some cancers, but has no effect on multiple sclerosis. Interferon gamma was also found to have no beneficial effect on multiple sclerosis. However, interferon beta has shown effectiveness as a multiple sclerosis treatment.

The active ingredient in AVONEX is a type of interferon called interferon beta-1a. Only Interferon beta-1a therapies (AVONEX and Rebif®) are indicated to reduce the number of flare-ups (relapses) and slow the accumulation of physical disability. Interferon beta-1b (Betaseron®) is only indicated for decreasing the number of flare-ups. The difference between interferon beta 1a and interferon beta 1b is in how they are made.

While the exact method by which interferon beta 1a achieves its beneficial effects in multiple sclerosis remains unknown, some researchers believe it may reduce inflammation. Studies looking at how interferon beta behaves in the lab suggest it may stop harmful cells from entering the brain. This theory has not been tested in people.

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