What is Avonex?
Avonex is a powder and solvent in a vial, to make a solution for injection, and a solution for injection in a pre-filled syringe. Each vial and each syringe contain 30 micrograms (6 million international units or MUI) of active substance, interferon beta-1a.
What is Avonex used for?
Avonex is used to treat the following groups of patients:
- patients suffering from relapsing multiple sclerosis (MS); it is a type of multiple sclerosis that causes recurrent seizures (relapses) that occur during periods when the patient has no symptoms. Avonex slows the progression of disability and decreases the number of relapses;
- patients who experience the symptoms of the disease for the first time if they are of such severity as to justify treatment with corticosteroid (anti-inflammatory) treatment, or when the patient is considered to have a high risk of developing multiple sclerosis. Before using Avonex, doctors must rule out that the symptoms are due to other causes.
Avonex is used in patients aged 12 years or older.
The medicine can only be obtained with a prescription.
How is Avonex used?
Treatment with Avonex should be started by a doctor experienced in the management of multiple sclerosis. The recommended dose of Avonex is 30 micrograms, given by intramuscular injection once a week. To help patients adjust the treatment, the doctor may recommend the patient to start with about half of this dose once a week and then increase to the full dose. This is only possible with the pre-filled syringe, if the syringe is equipped with a special device to attach to the syringe itself, which allows only about half of the Avonex dose to be injected.
The point at which the injection is made must vary every week. The patient can inject himself, provided he has been properly trained. Before each injection and in the following 24 hours the patient can take a painkiller with an antipyretic action (against fever) to alleviate the flu symptoms that may occur in the first few months of treatment. Treatment with Avonex should be discontinued in patients who develop progressive multiple sclerosis, ie who have a worsening of the disease.
How does Avonex work?
Multiple sclerosis is a nerve disease in which inflammation destroys the protective coating around the nerves. This is called "demyelination". The active substance in Avonex, interferon beta-1a, belongs to the class of interferons, natural substances produced by the body to fight, for example, infections caused by viruses. The mechanism of action of Avonex in the treatment of multiple sclerosis is not yet fully known, but it appears that interferon beta is able to regulate the immune system and thus prevent recurrence of the disease.
Interferon beta-1a is produced by a method known as "recombinant DNA technology": that is, it is obtained from a cell in which a gene (DNA) has been introduced which makes it capable of producing interferon beta-1a. The replacement interferon beta-1a behaves like naturally produced interferon beta.
How has Avonex been studied?
Avonex has been the subject of three main studies.
The first, conducted on 301 patients with relapsing multiple sclerosis, compared it with a placebo (a dummy treatment). Patients had had at least two relapses in the last three years or at least one relapse a year if they had had the disease for less than three years. Treatment continued for up to two years. The main measure of effectiveness was the number of patients whose disability had worsened.
The second study, conducted on 802 patients, compared the efficacy of the 60 micrograms dose with that of the 30 micrograms dose.
The third study, conducted on 383 patients who had a single crisis of demyelination, compared the effectiveness of Avonex with that of placebo in reducing the risk of a second crisis.
The company did not carry out formal studies on patients under the age of 16, but presented information derived from published studies on the use of Avonex in young people aged 12 to 18 years.
What benefit has Avonex shown during the studies?
In the first study, 22% of patients with relapsing multiple sclerosis treated with Avonex and 35% of patients treated with placebo experienced a worsening of disability by the end of two years. The second study showed no difference in efficacy between the two dosages. The third study showed that among patients who had a crisis of demyelination, those treated with Avonex had a lower estimated risk of a second crisis than those treated with placebo: for patients treated with Avonex the risk of a second crisis it was 21% over two years and 35% over three years, while the risk for patients treated with placebo was 39% over two years and 50% over three years respectively.
In patients aged 12 to 18 years, published studies show that these patients had a lower recurrence rate. This may be due to treatment with Avonex.
What is the risk associated with Avonex?
The most frequent side effects reported with Avonex (seen in more than one patient in 10) are headache, symptoms normally associated with influenza, pyrexia (fever), chills and sweating. These side effects decrease over time with continued treatment. Side effects in younger people are similar. For the full list of all side effects reported with Avonex, see the Package Leaflet.
Avonex should not be used in patients with a history of hypersensitivity (allergy) to natural or recombinant interferon beta, to human albumin or to any of the other components. The medicine sold in pre-filled syringe does not contain human albumin. Treatment with Avonex should not be started during pregnancy; if the pregnancy begins during treatment with Avonex, the patient should consult the doctor. Avonex should not be used in patients who suffer from severe depression or have suicidal thoughts.
Why has Avonex been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that the benefits of Avonex outweigh its risks for the treatment of patients who have been diagnosed with relapsing multiple sclerosis as well as patients who have had a single seizure of process demyelination active inflammatory, if it is severe enough to warrant intravenous corticosteroid injection. The Committee recommended that it be given marketing authorization.
Avonex was originally authorized "in exceptional circumstances" because, for scientific reasons, the data available at the time of approval were limited. As the company in the meantime provided the additional data requested, the restriction "in exceptional circumstances" fell on March 22, 2006.
More information on Avonex
On 13 March 1997, the European Commission issued a marketing authorization valid for Avonex, valid throughout the European Union. The authorization was renewed on March 13, 2002 and March 13, 2007. The marketing authorization holder is Biogen Idec Limited.
For the full EPAR for Avonex, click here.
Last update of this summary: 12-2008
