People with multiple sclerosis who took a beta interferon drug had a 32 per cent lower mortality risk than those that did not take the drug, a new study has found. The effect was particularly evident among MS patients who took beta interferon for more than three years.
“This is a significant study. Although these drugs have been prescribed since the mid-1990s, it takes time before scientists can look at the effect of these treatments on a long-term outcome like survival. We found that patients who were treated with these drugs during routine clinical practice survived longer overall than patients who had not taken beta interferon,"
said lead author Elaine Kingwell, a research associate and epidemiologist in the Djavad Mowafaghian Centre for Brain Health and the faculty of medicine at UBC, and Vancouver Coastal Health Research Institute.
The study, conducted by scientists from the University of British Columbia and Vancouver Coastal Health Research Institute, followed nearly 6,000 people with MS in Canada and France over a period of more than two decades. It is the first and largest observational study to look at mortality associated with beta interferon for the treatment of MS.
Multiple sclerosis (MS) is a disease that affects the central nervous system, in which cells from the immune system attack and damage the nerve cells' protective sheath. The disease often results in disability and can have a significant impact on quality of life.
The beta interferons were the first drugs to be approved for the treatment of relapsing-onset MS, which is the most common form of the disease. They have been used to treat MS longer than any other disease-modifying therapy.
Comparing Mortality Rates
The researchers followed 5,989 people with relapsing-onset MS from as early as 1986 until 2013, in British Columbia and France, to determine what disease modifying drugs they took and how long they survived.
The mean age of the study participants (who had not received drug treatments for MS before the start of the study) was 42 years. The mean age at death for the 742 people who did not survive to the end of the study was 61.
The findings were consistent between the two geographic groups and between men and women. MS patients who took beta interferon for at least six months had a reduced mortality risk when compared to MS patients who did not take beta interferon. Taking the drug for more than three years had an even stronger association with increased survival.
Moreover, increased survival was noted even for individuals who started the drug after age 40, or five or more years after disease onset.
Quality Of Life
Despite the positive findings, the researchers caution that longevity isn’t everything.
“Now that we know that life might be extended for people with MS who take these drugs, we do have to consider quality of life. Further research to look at this aspect of treatment outcomes is certainly warranted,"
said the study’s senior author Helen Tremlett, professor in the division of neurology at UBC and the Canada Research Chair in neuroepidemiology and multiple sclerosis.
The researchers hope to now look at the association of survival with some of the newer MS drugs.
Elaine Kingwell, Emmanuelle Leray, Feng Zhu, John Petkau, Gilles Edan, Joel Oger, Helen Tremlett Multiple sclerosis: effect of beta interferon treatment on survival Brain, awz055, https://doi.org/10.1093/brain/awz055
Image: Jslipscomb CC BY-SA 3.0. Crystal structure of human interferon beta at 2.2-A resolution.