The Facts About AVONEX
The Facts About AVONEX®
~ Information provided by Biogen, manufacturers of Avonex ~
What Is it?
Avonex by Biogen, Inc. is a form of interferon beta. Interferons are proteins produced naturally by the human body. Interferons help fight viral infections and help regulate the immune system. Avonex is made up of exactly the same amino acids as the natural interferon beta found in the human body. Avonex is manufactured commercially using a biotechnology process. No one knows exactly how Avonex works in MS, but it is believed to produce its beneficial effects by regulating the body's immune response against myelin, the fatty insulation surrounding nerve fibers.
The main goal of therapy with Avonex is to slow the natural progression of disability that occurs in relapsing MS. Earlier MS treatments centered on making symptoms less severe. More recently, doctors began using another form of interferon beta (Interferon beta-1b) to help reduce exacerbations (flare-ups of symptoms). Avonex, a new form of interferon beta, reduces exacerbations and is also the only medication proven to slow the permanent disability caused by the disease.
How It's Administered
Avonex is administered once-a-week through intramuscular injections. The injection is usually given in the large muscles of the thigh and upper arm.
What It Does
Data reported by Biogen from clinical trials indicates that Biogen's interferon beta-1a slows the accumulation of physical disability and decreases the frequency of acute attacks in people with active relapsing-remitting forms of multiple sclerosis, but at the moment we don't know why.
While interferon beta combats viral infections, both in cells grown in the laboratory, and in laboratory animals, it is most likely that this agent is acting as a medulator of immune system function rather than as an antiviral treatment. Inspired by the results of the clinical trial, a growing number of scientists are investigating the "whys" of Interferon beta. Their studies will not only answer these questions, but also they should provide clues to the best ways to use Avonex against MS and suggest the development of even more effective treatments.
Study Details
Avonex was studied in people with relapsing-remitting MS in a major multi-year clinical study. The study compared people treated with Avonex to a control group.
People in the study were evaluated at the beginning, during, and end of the study. Results of the study showed that treatment with Avonex benefited people with MS in two ways: slowing the progression of disability and fewer exacerbations.
Slowing the progression of disability
People treated with Avonex maintained their existing level of function longer. Overall, treatment with Avonex reduced the risk of disability progression by 37%.
Fewer people treated with Avonex progressed to a state of severe disability (only 5% [8 out of 148] of people in the Avonex group vs 14% [19 out of 132] of people in the control group), or to a state requiring a cane or crutches to walk (only 1% [2 out of 148] of people in the Avonex group vs 7% [9 out of 132] of people in the control group).
Fewer exacerbations
As a group, people treated with Avonex experienced fewer exacerbations. In fact, people taking Avonex for 2 years had 1/3 fewer exacerbation that the people in the control group. Furthermore, 38% (32 out of 85) of people on Avonex had no flare-ups at all during the 2-year period. Only 26% (23 out of 87) of people receiving placebo remained exacerbation-free during that time.
Avonex-treated patients who did have exacerbations were less likely to have frequent exacerbations (3 or more) over 2 years than patients on placebo. For people with MS, this means having fewer periods where symptoms interfere with normal daily living.
In addition, MRI (magnetic resonance imaging) brain scans given after 1 and 2 years of treatment showed that Avonex (compared to placebo) significantly reduced the number and size of active lesions of the brain caused by MS. The exact relationship between MRI findings and the clinical status of patients is unknown.
Exacerbations and lesions see on MRI scans are important signs of disease activity in MS. However, neither are necessarily related to a person's level of disability. Improvement in either exacerbations or MRI lesions is important, but does not automatically result in slowing of disability progression. That's why the clinical study with Avonex is so important. The study showed that Avonex can slow the progression of disability.
It is important to understand that the results of a clinical study represent a group average, not individual results. Individual responses can be different. Therefore, the overall study results can't predict exactly what you will experience if you are treated with Avonex.
Side Effects of Treatment
Most people treated with Avonex have adjusted well to their therapy. However, as with any other prescription medication, side effects can occur. Particularly at the beginning of the therapy, people may experience flu-like side effects. The following table shows the percentage of people who experienced these side effects in the clinical study. Most patients experienced one or more of these side effects on at least one occasion during the study. These reaction usually subside within a day after an injection. Also, these side effects tend to occur less often as therapy goes on.
Symptoms |
Avonex |
Placebo |
Unspecified flu-like symptoms |
61% |
40% |
Muscle ache |
34% |
15% |
Fever |
23% |
13% |
Chills |
21% |
7% |
Weakness |
21% |
13% |
During the clinical study, only 4% (6 out of 158) people receiving Avonex experienced skin reaction at the injection site.
Pregnancy
You should not use Avonex if you are pregnant or are trying to become pregnant. If you wish to become pregnant and are using Avonex, discuss this matter with your doctor. If you are of childbearing age, you should use birth control while on Avonex. Should you become pregnant while on Avonex, stop treatment and contact your doctor right away.
Contact Information
You can call the Avonex Support Line 8:30 am to 8:00 pm EST, Monday through Friday at 1-800-456-2255, or visit the Avonex website at http://www.avonex.com.
~ Information provided by Biogen, manufacturers of Avonex ~
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