Interferon beta-1a (trade name Avonex, Rebif, or CinnoVex) is used to treat relapsing forms of multiple sclerosis (MS). It is genetically engineered to simulate a naturally occurring protein produced by mammalian cells. In February 2003, the US Food and Drug Administration (FDA) approved Avonex, which is made by Biogen Incorporated, for early treatment of the disease. It has been on the market since 1996, however, and over 130,000 patients have used it.
MS is a chronic disorder that affects movement, sensation, and bodily functions. Although it occurs when the protective sheath (myelin) surrounding nerve fibers (neurons) is destroyed, its cause is unknown. It is nevertheless considered an autoimmune disease of the central nervous system.
About 30 percent of MS patients experience a relapsing-remitting form of the disease. In these cases, symptoms disappear or lessen for months or even years between flare-ups.
Interferon-based medications have been shown to reduce relapses by about 30-35 percent and to slow the progression of MS's resulting disabilities. It is believed that these beneficial effects are due to the medications' anti-inflammatory properties and ability to improve the integrity of the blood-brain barrier (BBB).
Unfortunately interferons, as these medications are known, also have side effects. The principal ones are flu-like symptoms and injection-site reactions, but they may also include:
- Elevation of liver enzymes
- Blood cell abnormalities
In fact, Biogen admitted that in rare cases, Avonex might have caused severe liver injury, including liver failure. But rather than removing Avonex from the market, Biogen merely changed the drug's label to include a "warning", rather than the previous advisory regarding potential liver damage.
The labeling change took place just weeks after Tysabri, a newer Biogen drug sometimes used in combination with Avonex, was suspended from the market after reports it may have caused progressive multifocal leukoencephalopathy (PML), a rare brain disease, in two patients, one of whom died.
If you suspect that a loved one is suffering adverse effects or has died as a result of using Avonex, you may wish to consider filing a claim. Contact an experienced defective pharmaceutical injury attorney to evaluate your case.
Contact PersonalInjury.com today to find an experienced pharmaceutical injury lawyer near you.