Etiology of the Disease
Also, the etiology of the disease is far from clear. MS appears to be autoimmune in nature, and there is evidence to suggest some combination of genetic and environmental factors. About 15% of multiple sclerosis patients have an affected relative, but no single gene has been identified as responsible. The current theory is that the disease occurs in people with a genetic susceptibility who are also exposed to some environmental factors that disrupt the blood-brain barrier.
A number of disease patterns have been documented in multiple sclerosis patients, and some experts believe that multiple sclerosis may prove to be not a single disorder but several disorders with different causes.
However, despite the lack of a cure, several approved treatments are now available to slow the progression of the disease and offer improved quality of life for people living with this condition.
There are nine products in Phase III clinical trials that could become available before the end of the decade, and at least another 13 in Phase II. With no truly breathtaking breakthroughs in the offing, however, the MS market in the short term will be dominated by four major approved therapies: Avonex, Betaseron/Betaferon, Copaxone, and Rebif.
Avonex, marketed by Biogen Idec (www.biogenidec.com), is an interferon beta-1a approved for the treatment of relapsing forms of multiple sclerosis. Avonex is the leading treatment worldwide for multiple sclerosis with total sales reported at $1.7 billion in 2006. This approximately $1 billion is generated in the U.S.
Rebif, marketed by Merck Serono (www.serono.com), holds the second largest share of the worldwide market. Sales reached $1.5 billion in 2006. Additionally, the product is the leading treatment in terms of sales for the European region. Rebif is an interferon beta approved for the treatment of relapsing-remitting multiple sclerosis.
Marketed in 47 countries worldwide, Copaxone is another big multiple sclerosis treatment. Sales for Copaxone reached $1.4 billion in 2006, an increase from $1.2 billion in 2005. Copaxone is a noninterferon therapy indicated for reducing the frequency of relapses in patients with relapsing-remitting MS. Copaxone is marketed in the U.S. and Canada by Teva (www.tevapharm.com) and distributed by sanofi-aventis (www.sanofi-aventis.com).
Betaferon, marketed by Bayer(www.bayer.com) in the U.S. as Betaseron, is also a leading multiple sclerosis treatment. Sales for Betaseron/ Betaferon exceeded $1.2 billion in 2006, increasing from $1.1 billion in 2005. Betaferon is manufactured by Chiron (now part of Novartis; www.novartis.com) for North American countries, Japan, and other select countries; while Boehringer Ingelheim (www.boehringer-ingelheim.com) manufactures the drug for European markets.