What are biosimilars? - woman in lab / goggles

Biosimilars - what are they?

Comparable to reference products in biological activity and safety

A biosimilar is a drug that is highly similar to another approved biologic drug despite minor differences in clinically inactive components. Biosimilars exhibit no clinically meaningful differences in terms of efficacy and safety from the reference biologic drug.1

Biosimilar development

Biosimilars go through rigorous comparative testing against the authorized reference biologic drug including:1

  • Characterization and analytical studies to demonstrate that the biosimilar is highly similar to the reference biologic product in terms of its molecular characteristics
  • Clinical studies to confirm comparative efficacy, safety, pharmacokinetics and pharmacodynamics demonstration only if possible (i.e., existing PD markers) in a sensitive population/indication or more appropriate conditions of use for which the reference product is approved 

Differences between reference products and biosimilars

Since biological medicines are created from living cells, slight differences may occur between a biosimilar and its reference product. These differences do not involve the “medicinal” part of the biosimilar and are not known to affect how the medicine works in the body.2

In the example below, the arrow points to a minor difference in the sugar chains present on the reference and biosimilar molecules.2

What are biosimilars FIG 1

Differences between product batches

Biologic medicines are made in “batches”. During the manufacturing process, variability between different batches of the same biosimilar molecule is expected, and is carefully monitored by regulatory authorities such as Health Canada. These acceptable, within-product differences are not known to affect safety, efficacy or patient outcomes.2 

What is biosimilars Fig 2

How biosimilars are approved in Canada

Health Canada has developed a robust, science-based framework for authorizing biosimilars. Biosimilars must be manufactured to the same regulatory standards as other biologic drugs and authorized after scientific evaluation by Health Canada.1

Health Canada requires that biosimilar manufacturers demonstrate the similarity of their biosimilar to the reference biologic drug via a step-wise approach:1

  • Beginning with structural and functional studies
  • Continuing with human clinical studies

Biosimilar manufacturers must independently demonstrate the quality of their product and perform comparative studies to demonstrate highly similar structure, function, efficacy and safety to the reference biologic.1

Biosimilars have been approved for use in Canada since 2009.3 Currently, 24 biosimilars are approved or marketed in Canada, with another 14 biosimilars currently under review. Five of those under review are for autoimmune diseases.3,4

Biosimilars - why choose them? Learn here

Health Canada. Biosimilar biologic drugs in Canada: fact sheet. Accessed June 22, 2020 at: www.canada.ca/content/dam/hc-sc/migration/hc-sc/dhp-mps/alt_formats/pdf/brgtherap/applic-demande/guides/Fact-Sheet-EN-2019-08-23.pdf.
2. European Medicines Agency (EMA). Biosimilars in the EU: Information guide for healthcare professionals. 2017. Accessed June 26, 2020 at: www.ema.europa.eu/docs/en_GB/document_library/Leaflet/2017/05/WC500226648.pdf.
3. Health Canada. Drug Products NOC Database. Accessed June 22, 2020 at: www.health-products.canada.ca/noc-ac/index-eng.jsp.
4. Health Canada. Drug and Health Product Submissions Under Review (SUR). Accessed June 22, 2020 at: www.canada.ca/en/health-canada/services/drug-health-product-review-approval/submissions-under-review.html.