Author: Bhavesh Patel
This past August, Health Canada published a document titled “Biosimilar Biologic Drugs in Canada: Fact Sheet” to provide a comprehensive overview on a number of issues concerning biosimilar biologic drugs (also referred to as “subsequent entry biologics”).
A biosimilar biologic drug, or biosimilar, is a biologic drug that is highly similar to a biologic drug already authorized for sale (the “reference biologic drug”). There are no expected clinically meaningful differences in efficacy and safety between a biosimilar and the reference biologic drug. Biosimilars are authorized for sale following a thorough comparison to the reference biologic drug, and may enter the market following the expiry of the relevant patents and data protection pertaining to the reference biologic drug. Health Canada authorizes biosimilars for sale using the same rigorous regulatory standards for quality, efficacy, and safety applicable to all other biologic drugs.
Biologic drugs are drugs manufactured using living organisms or their cells. Examples of biologic drugs include insulin, growth hormones and antibodies. Biologic drugs are used to treat diseases and medical conditions including anemia, diabetes, psoriasis, hormone deficiency, rheumatoid arthritis, some forms of cancer, and inflammatory bowel disease.
Although biosimilars are often considered “generic” biologics, they differ from traditional generic drugs in several important aspects. In particular, as biosimilars are manufactured through living organisms or cells, the drug molecules are large and complex, unlike traditional generic drugs which are chemically synthesized “small molecule” drugs. In terms of the drug molecule, traditional generic drugs are identical to the reference product, in biosimilars, the drug molecule almost always differs from the reference biologic drug.
In Canada, the biosimilars regulated as new drugs under the Food and Drugs Act and the Food and Drug Regulations.
Information requirements for initial authorization of a biosimilar
Biosimilar sponsors must provide information to Health Canada to demonstrate the similarity of the biosimilar to the reference biologic drug. This proceeds according to a step wise approach beginning with structural and functional studies, and continuing with human clinical studies.
Because the purpose of these studies is to demonstrate similarity, the type of data required to support biosimilar authorization differs from that required for the reference biological drug. To obtain authorization to sell a new active substance (which would be contained in a reference biologic drug), sponsors must independently demonstrate the quality, efficacy and safety of the drug. Generally, authorization of an innovator drug requires "pivotal" phase III clinical trials to establish efficacy and safety in each disease or medical condition that the drug is intended to treat. With respect to biosimilars, sponsors must independently demonstrate the quality of the drug and perform comparative studies to demonstrate highly similar structure, function, efficacy and safety to a previously authorized reference biologic drug.
Indications
A biosimilar may be authorized for all or some of the indications as the reference biologic drug. The indications depend on factors such as the indications the sponsor desires for the biosimilar, and indications under intellectual property protection (which cannot be authorized until the protection expires).
Health Canada also assess the immunogenicity of biosimilar drugs, and will request a Risk Management Plan for all biologic drugs, including biosimilars. This plan explains how the manufacturer will monitor immunogenicity after the biosimilar has been authorized.
Health Canada has not observed unexpected post-authorization safety signals for biosimilars marketed in Canada. The efficacy and safety profiles of biosimilars authorized in Canada remain in line with those of their reference biologic drugs. Health Canada receives drug safety information from other jurisdictions including the United States and the European Union. Biosimilars have been used for over 10 years in the European Union and unexpected safety signals have not been identified.
For more information on safety-related updates to biosimilar product monographs, naming convention for biologic and biosimilar drugs, adverse drug reaction reporting, interchangeability, switching and advertising please see bellow provided link.
Reference:
Health Canada: Biosimilar drugs Fact sheet dated August 23, 2019
https://www.canada.ca/en/health-canada/services/drugs-health-products/biologics-radiopharmaceuticals-genetic-therapies/applications-submissions/guidance-documents/fact-sheet-biosimilars.html