On June 10, 2025, Health Canada released a draft revision to its Guidance Document: Information and Submission Requirements for Biosimilar Biologic Drugs, opening a consultation period that runs until September 8, 2025.

A key shift in the updated draft is the proposal to no longer require biosimilar manufacturers to prove the safety and efficacy of their product through phase III clinical trials. If finalized, this would mark a pivotal change in Canada’s regulatory approach.

What’s changing?

Sponsors developing biosimilars in Canada are generally expected to conduct a comparative phase III clinical study to establish a lack of clinically meaningful differences between the biosimilar and the Canadian Reference Biologic Drug (CRBD). This study typically included hundreds of patients and aimed to detect any potential clinical differences in efficacy, safety, or immunogenicity between the biosimilar and its reference product.

Under the draft guidance, Health Canada proposes to do away with a comparative clinical efficacy and safety trial in most cases:

Existing guidelines

Proposed new guidelines

Clinical efficacy trial(s)

In most cases, a comparative clinical trial(s) is important to rule out clinically meaningful differences in efficacy and safety between the biosimilar and the reference biologic drug. A clinical efficacy trial may not always be necessary, e.g. where there is a clinically relevant PD endpoint. In such cases, a scientific justification is needed and safety as well as comparative immunogenicity data are still required.

Comparative clinical efficacy and safety trial(s)

In most cases, a comparative clinical efficacy and safety trial(s) is not required. Safety and comparative immunogenicity data are still required and should be collected within the comparative clinical pharmacology studies but could be supplemented with data collected using other trial designs (e.g., studies designed to specifically focus on safety and/or immunogenicity). If a comparative clinical efficacy and safety trial(s) is deemed necessary, sponsors should provide a rationale to explain the purpose of the trial(s) in the context of a biosimilar submission.


The proposed new guidelines suggest that a comparative pharmacokinetic (PK) study and, if feasible, a comparative pharmacodynamic (PD) evaluation should be included in the biosimilar’s NDS:

2.2.3.3 Clinical studies

The purpose of the clinical program of a biosimilar candidate is to support a demonstration of a high degree of similarity derived from the comparative analytical assessments of the physicochemical characteristics, functional properties, and stability profiles between the biosimilar candidate and the CRBD.

The clinical program should primarily include a comparative pharmacokinetic study, and if feasible, a comparative evaluation of pharmacodynamics. These studies may be followed by an additional clinical trial(s) in exceptional circumstances.

Numerous other changes are proposed in the guidance document, many of which follow-on from the proposed change in no longer requiring support from clinical trial(s).

For instance, the new guidance signals a shift in how Health Canada will consider the authorization of biosimilar indications. The new guidance removes language from the existing guidance that speaks to the need for a detailed rationale justifying authorization of the biosimilar in each indication of the CRBD based on, among other things, the data derived from the biosimilar’s clinical studies.

Additionally, biosimilar product monographs can be expected to change, with the comparative clinical data that is found in current biosimilar monographs no longer forming part of the biosimilar drug submission.

Other jurisdictions and next steps

Regulators in other jurisdictions have signalled an intent to consider reducing clinical trial requirements for biosimilar manufacturers. The EMA has released a “reflection paper on a tailored clinical approach in biosimilar development” that is open to consultation until September 30, 2025.  Underlying the proposed approach is the “notion that under specific prerequisites, analytical comparability exercises and pharmacokinetic (PK) data could be sufficient for demonstrating biosimilarity.”

In the United States, on April 10, 2025 President Trump signed an Executive Order with a mandate for the Secretary of Health and Human Services, through the Commissioner of Food and Drugs, to issue a report providing administrative and legislative recommendations to accelerate approval of biosimilars within 180 days.

This followed an April 10, 2025 bill that was introduced by Senator Rand Paul—the Expedited Access to Biosimilars Act—which would “amend the Public Health Service Act to provide that clinical studies required for licensure of biological products as biosimilar shall not be required to include the assessment of immunogenicity, pharmacodynamics, or comparative clinical efficacy.” It has been reported that some potential biosimilar entrants have terminated or minimized phase 3 trials for biosimilar products such as pembrolizumab after discussions with the FDA.

As mentioned, Health Canada is gathering feedback until September 8, 2025, seeking input from industry, academics, health system partners, and the public. The outcome may have lasting impacts on Canada’s biosimilar landscape.

If you have any questions about the new guidelines and the consultation period, please reach out to the authors or a member of Gowling WLG’s Life Sciences sector group.