Theres new hope in the fight against multiple sclerosis (MS), the most common neurological disorder affecting young people in North America. Study results published today in The New England Journal of Medicine showed that people at high risk for MS taking the drug AVONEX(r) (Interferon beta-1a) experienced a 44 per cent reduction in progression to clinically definite MS versus treatment with placebo.
Interim results from the high-profile CHAMPS (Controlled High Risk Subjects AVONEX Multiple Sclerosis Prevention Study) were so impressive that the study committee recommended stopping the study after two years -- a year earlier than scheduled.
Patients in CHAMPS -- a randomized, double-blind, placebo-controlled, Phase III trial -- had experienced a recent "demyelinating event" but did not yet have clinically definite multiple sclerosis (CDMS). Demyelination, considered a sign of multiple sclerosis, is destruction of myelin, the protective coating of the nerves in the central nervous system.
There are no well-accepted guidelines for the treatment of such patients. CDMS is defined as occurring after a patient has had not one, but two demyelinating events, separated by time and location in the central nervous system.
The 383 patients enrolled in the study among which approximately 30 per cent were Canadian, had a high probability of developing CDMS, determined by brain magnetic resonance imaging (MRI) studies and clinical events suggestive of multiple sclerosis.
Participants received weekly intramuscular injections of either 30 micrograms of AVONEX or placebo. The study was conducted at 50 clinical centers in North America, including eight in Canada.
"AVONEX is already used by patients who have relapsing multiple sclerosis to slow progression of disability, and to reduce the frequency of flare-ups," said investigator Dr Pierre Duquette, chairman of the division of neurology and the head of the MS clinic at Nôtre-Dame Hospital in Montreal, Quebec. "However, the new study shows that AVONEX can be used to delay the development of CDMS in people with only early signs of the disease. This is really important for the well-being of patients."
"AVONEX also showed a very positive impact in reducing the rate at which patients developed brain abnormalities, or lesions, visible on MRI scans," said investigator Dr Douglas Arnold, director of The Clinical Research Unit at The Montreal Neurological Institute in Montreal, Quebec.
"By showing a strong benefit of early AVONEX treatment, CHAMPS enhances the justification for obtaining brain MRI at the earliest symptoms of MS," Dr Arnold said. "In the past, MRI had been considered useful, but not necessary. The findings on MRI did not affect treatment."
In summary, CHAMPS showed that compared to placebo, in the AVONEX treated arm the:
- rate of development of CDMS was 44 per cent lower;
- brain T2 lesion volume was 91 per cent lower at 18 months; and,
- mean number of gadolinium-enhanced lesions was 67 per cent lower at 18 months, based on MRI scans.
"AVONEX is the first MS therapy proven in a published study to reduce the rate at which high-risk individuals develop clinically definite multiple sclerosis," said Dr Duquette. "In addition to its previously demonstrated benefits, our results show that initiating once-weekly intramuscular injections of 30 mcg of AVONEX, the currently approved dose, beginning at the time of a first MS attack, is beneficial in patients who have brain MRI evidence of prior demyelination."
Echoing the responses of study investigators, Dr Adel Gehshan, medical director at Biogen Canada said, "Everything we continue to learn about AVONEX in the treatment of MS supports the treat early recommendations issued by the Canadian MS Clinics Network."
Multiple sclerosis is a chronic disease of the central nervous system that affects approximately 50,000 Canadians and about one million people worldwide. More than 20 new cases of multiple sclerosis are diagnosed weekly in Canada alone. MS begins in young adults, mostly women, typically between 20 and 40 years of age. Symptoms may include vision problems, loss of balance, numbness, difficulty walking and eventually paralysis.
It is believed the disease occurs when the immune system destroys myelin, the fatty sheath that surrounds and protects nerve fibers and facilitates the flow of nerve impulses to and from the brain. The loss of myelin disrupts the conduction of nerve impulses, producing the symptoms of multiple sclerosis.
AVONEX(r) (Interferon beta-1a) is currently indicated for the treatment of relapsing forms of multiple sclerosis to slow down the progression of disability, decrease the frequency of clinical exacerbations, and reduce the number and volume of active brain lesions identified on magnetic resonance imaging (MRI) scans. The data from CHAMPS have been submitted to Health Canada to expand the indication to include patients who have experienced a single demyelinating event.
AVONEX was approved in Canada in May 1998 and is the leading treatment for MS globally. More than 90,000 patients worldwide are now on AVONEX which is marketed in more than 60 countries.
Biogen Inc.s, research and development activities are focused on novel products for multiple sclerosis, inflammatory, respiratory, kidney and cardiovascular diseases and in developmental biology and gene therapy.