Food and Drug Administration Approvals, March 2003
Medscape Pharmacists 4(1), 2003
Manufacturer: Biogen, Inc.
Drug Approval Classification: Biologics License Application Supplement (Approval Date: 1/31/03)
New Indication: Avonex (interferon beta-1a) has received FDA approval to include a new indication in patients who have experienced a first clinical episode of multiple sclerosis (MS) and have magnetic resonance imaging (MRI) features consistent with MS.
Dosing: The recommended dosage of Avonex is 30 mcg injected intramuscularly (IM) once a week.
Clinical Summary: The supplemental indication for the treatment of a first clinical episode with interferon beta-1a was based on a single randomized, double-blind trial of 383 patients who had a first acute clinical demyelinating event (optic neuritis, incomplete transverse myelitis, or brain-stem or cerebellar syndrome) and evidence of prior subclinical demyelination on MRI of the brain. Patients enrolled in the CHAMPS study received 30 mcg interferon beta-1a or placebo by IM injection once weekly for 2 years and followed up to 3 years or until a second clinical exacerbation.
The primary end point was time from the first to a second MS attack. Within 24 months, 38.6% of patients treated with interferon beta-1a developed an exacerbation of MS.
Avonex-treated subjects experienced a 44% decrease in the rate of developing a second attack when compared with placebo.
Jacobs LD, Beck RW, Simon JH, et al. Intramuscular interferon beta-1a therapy initiated during a first demyelinating event in multiple sclerosis. CHAMPS Study Group. N Engl J Med. 2000;343:898-904.
Adverse Effects: The FDA approval letter for this supplemental indication for Avonex included the request for a patient Medication Guide. Due to serious adverse events based on postmarketing experience, the following Avonex safety information has been revised:
Avonex (interferon beta-1a) Labeling
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