Summary Safety Review - AVONEX (interferon beta-1a) - Assessing the Potential Risk of Kidney Damage (nephrotic syndrome)
Review decision
A Summary Safety Review complements other safety related information to help Canadians make informed decisions about their use of health products. Each summary outlines what was assessed in Health Canada’s review, what was found and what action was taken by Health Canada, if any.
Issued: 2016-06-30
Product
Avonex (interferon beta-1a)
Potential Safety Issue
Kidney damage (nephrotic syndrome)
Overview
Use in Canada
- Avonex is used to treat some forms of multiple sclerosis, to reduce damage to the central nervous system, and to slow down the worsening of the disease. Avonex is given by injection into the muscle at a dose of 30 micrograms once a week.
- Avonex has been marketed in Canada since December 2005. It is available by prescription only.
Safety Review Findings
- At the time of the review, there was only 1 Canadian case of nephrotic syndrome reported in a multiple sclerosis patient using Avonex.
- A search in the World Health Organization's Adverse Drug Reaction Database found 10 cases of nephrotic syndrome reported in multiple sclerosis patients treated with interferon beta products.
- In the scientific and medical literature, there were 7 cases of nephrotic syndrome found with the use of interferon beta products.
- In addition, the manufacturer shared a report from the Global Safety Database which contained 9 cases of nephrotic syndrome with Avonex. Upon review of these cases, they were considered to be possibly related to the use of Avonex.
- Information regarding the risk of nephrotic syndrome is already included in the prescribing information for all other interferon beta products in Canada (i.e., Betaseron, Rebif, and Extavia). Information on the risk of nephrotic syndrome appears in the European product labelling for all interferon beta drugs.
Conclusions and actions
- Health Canada's safety review concluded that there is a potential risk of nephrotic syndrome with the use of Avonex for the following reasons:
- nephrotic syndrome has been linked to other interferon beta drugs;
- nephrotic syndrome has been reported with Avonex treatment;
- Avonex causes changes in the body which might bring about nephrotic syndrome as a side-effect;
- Health Canada has asked the manufacturer to update the Canadian prescribing information to include this risk.
- Health Canada continues to monitor side effect information involving Avonex, as it does for all health products on the Canadian market, to identify and assess potential harms. Health Canada will take appropriate and timely action if and when any new health risks are identified.
Additional information
The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this drug both in Canada and internationally.
For additional information, contact the Marketed Health Products Directorate.