Avonex® (interferon beta
Drug Identification Number (DIN) 02237770; 02269201 (pre-filled syringe)
Avonex (interferon beta 1a) is a type of protein called a beta-interferon that is produced from mammalian cells using recombinant DNA techniques (a series of procedures used to join together DNA segments). Beta interferon occurs naturally in the human body in response to initiating factors such as viruses.
Avonex is approved for the treatment of:
Avonex is self-injected once per week into the muscle (intramuscularly). The medication is available as a pre-filled syringe (Avonex® PS) and pre-filled auto-injector (Avonex® Pen). The recommended dose of Avonex is 30 mcg once per week.
The main effects of Avonex are to block the activity of certain immune system cells and to reduce the passage of these immune cells into the central nervous system, where they cause inflammation and damage to myelin (the insulating material that protects nerves and helps them work properly).
The most common side effects of Avonex therapy include flu-like symptoms (fever, chills, sweating, muscle aches and tiredness) and injection site reactions.This is not a comprehensive list of all possible side effects of Avonex. Please see the Avonex product monograph product monograph for a list of other potentially serious side effects. It is important that those with MS discuss side effects about any medication they are considering with their physician. (*Health Canada, product monograph for Avonex.)
Some people taking a beta-interferon therapy develop neutralizing anti-bodies (NAb). It is not known if NAbs completely “neutralize” the clinical benefits of therapy. Some research has found that a higher NAb level may be associated with a lesser treatment effect. The level of NAbs associated with the use of Avonex is lower than that seen during treatment with the other beta-interferons. Studies are continuing in this area, as is the development of a standardized NAb test.
Clinical Trials in Relapsing-Remitting MS
MSCRG Study: Multiple Sclerosis Collaborative Research Group StudyIn this clinical trial, 301 people with relapsing-remitting MS were treated with either Avonex at a dose of 30 mcg once per week or placebo (a treatment that has no active medication) for over 2 years. Results of the study showed that Avonex delayed the time to sustained progression of disability compared to placebo. The proportion of patients who progressed was reduced 37% (21.9% vs. 34.9%). Avonex reduced the annual attack rate by 18-32% compared to placebo and also reduced the number of brain lesions on MRI.1 [Jacobs et al. Ann Neurology 1996; 39: 285-294]
Clinical Trials: Single Event Suggestive of MS
CHAMPS Study: Controlled High-Risk Subjects Avonex Multiple
Sclerosis Prevention Study
This study examined whether Avonex could reduce conversion to clinically definite MS in people who had a single neurological event suggestive of MS (an event involving the optic nerve, brain stem/cerebellum, or spinal cord) but who had not been diagnosed with MS. A total of 383 persons were treated with Avonex or placebo for up to 3 years. Treatment with Avonex resulted in a 44% reduction in the chance of having a second MS attack over the three-year period.2 [Jacobs et al. N Engl J Med 2000; 343: 898-904]
The price of Avonex is approximately $20,000 per year. Much of the cost can be reimbursed through private and group health plans for people who meet the prescribing criteria and through provincial drug programs for individuals who meet the prescribing criteria.
Further information for persons with MS is available from Biogen ONETM program at 1-855-MSONE-00 or 1-855-676-6300.
Avonex® is a registered trademark of Biogen Canada Inc.