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The Canadian biosimilar market is entering a period of significant transformation. On June 10, 2025, Health Canada proposed draft guidance that would eliminate the requirement for biosimilar manufacturers to conduct phase 3 clinical trials, a change that, if finalised, could accelerate market entry timelines by years and fundamentally reshape the patent litigation landscape for biologic drugs in Canada.
For innovator pharmaceutical companies and biosimilar manufacturers alike, these regulatory shifts create both opportunities and challenges. Navigating this evolving environment requires guidance from an experienced ip law firm in Toronto with deep expertise in pharmaceutical patent litigation. Earlier regulatory submissions will trigger earlier patent disputes under Canada’s linkage regime, compressing timelines and requiring more proactive litigation strategies.
This article examines the proposed regulatory changes, the current state of biosimilar patent litigation in Canada, and what in-house counsel and business leaders should be doing now to prepare for the coming wave of disputes.
The Regulatory Shift: Health Canada’s Proposed Guidance
On June 10, 2025, Health Canada launched a consultation on proposed revisions to its Guidance Document: Information and Submission Requirements for Biosimilar Biologic Drugs. The consultation period closed on September 8, 2025, and while the final guidance has not yet been issued, the proposed changes signal a significant shift in Canada’s approach to biosimilar regulation.
The Key Change: Eliminating Phase 3 Clinical Trials
Under Health Canada’s current guidance, biosimilar manufacturers are generally expected to conduct a comparative phase 3 clinical study to demonstrate no clinically meaningful differences between their product and the Canadian Reference Biologic Drug (CRBD). These trials typically enrol hundreds of patients, run for approximately 55 weeks, and cost an estimated $28 million USD (based on 2021 median figures from 29 trials reported in JAMA Internal Medicine).
The draft guidance would reverse this requirement. Under the proposed approach, comparative clinical efficacy and safety trials would not be required in most cases. Instead, biosimilar clinical programs would be “generally limited” to a comparative pharmacokinetic (PK) study to demonstrate PK equivalence, plus an assessment of immunogenicity and safety data collected within those studies.
The draft guidance also removes the requirement for a “detailed rationale” justifying authorisation of the biosimilar in each indication of the CRBD based on data from the biosimilar’s own clinical studies. This change reflects a shift toward emphasising “a high degree of similarity” established through extensive comparative quality studies rather than clinical trial outcomes.
International Context: A Global Trend
Health Canada’s proposal aligns with international regulatory trends. On April 1, 2025, the European Medicines Agency (EMA) published a draft reflection paper suggesting that clinical evidence of efficacy “may no longer be required for approval of biosimilars.” The EMA’s consultation remains open until September 30, 2025.
In the United States, the Expedited Access to Biosimilars Act was introduced in the Senate on April 10, 2025, proposing that clinical studies for biosimilar approval “shall not be required to include the assessment of immunogenicity, pharmacodynamics, or comparative clinical efficacy.” Several biosimilar manufacturers have already responded to FDA signals by terminating or minimising phase 3 trials, most notably for pembrolizumab (KEYTRUDA) biosimilars, with Formycon terminating its phase 3 trial in February 2025 and Sandoz announcing plans to minimise its trial in April 2025.
The United Kingdom’s Medicines and Healthcare products Regulatory Agency has gone even further, having stopped requiring clinical evidence of efficacy for biosimilars in a 2021 guidance.
Impact on Patent Litigation Timing
The practical consequence of eliminating phase 3 trial requirements is straightforward: biosimilar manufacturers will be able to file New Drug Submissions (NDSs) earlier. Under Canada’s patent linkage regime, the Patented Medicines (Notice of Compliance) Regulations (PMNOC Regulations), earlier submissions mean earlier patent disputes.
How the Linkage System Works
Canada’s PMNOC Regulations create a “linkage” between regulatory approval and patent rights. When a biosimilar manufacturer (the “second person”) files an NDS with Health Canada, it must address each patent listed on the Patent Register against the reference product. If the manufacturer alleges that the listed patents are invalid or not infringed, it must serve a Notice of Allegation (NOA) on the innovator (the “first person”).
The innovator may then commence a section 6(1) action in the Federal Court within 45 days. If it does, a 24-month statutory stay prevents Health Canada from issuing a Notice of Compliance (NOC) to the biosimilar manufacturer until the earlier of: (a) the expiry of 24 months, or (b) a court decision in favour of the biosimilar manufacturer.
With phase 3 trials no longer required, biosimilar manufacturers will be able to complete their regulatory dossiers sooner. This means innovators may face litigation earlier than they had previously anticipated, potentially by 12 to 18 months or more.
The Current Biosimilar Litigation Landscape
To understand where the biosimilar market is headed, it is instructive to examine recent litigation activity and trends.
Litigation Statistics: A Decline in New Actions
According to Health Canada’s Statistical Report 2024/2025 for the PMNOC Regulations, 33 actions were filed under section 6 of the Regulations in 2024–2025, a decrease from 39 in 2023–2024 and 53 in 2022–2023. This marks the second consecutive year of decline in new filings.
Interestingly, the number of biosimilar and generic submissions to Health Canada increased to 115 in 2024–2025 (up from 107 the prior year). The divergence between rising submissions and declining litigation suggests that more disputes are being resolved through settlement before reaching trial. Of the approximately 326 actions commenced since the 2017 amendments to the PMNOC Regulations, the majority (264) have been resolved without a decision on the merits, almost always prior to trial.
High-Profile Biosimilar Disputes
Several significant biosimilar patent disputes are currently active or recently concluded in Canadian courts:
Eculizumab (SOLIRIS) – Alexion v. Amgen and Samsung Bioepis
In Alexion Pharmaceuticals, Inc. v. Amgen Canada Inc., 2025 FC 754, the Federal Court granted Alexion a declaration of infringement and an injunction preventing Amgen from manufacturing, using, or selling its biosimilar eculizumab product, BEKEMV, in Canada until the expiration of Alexion’s Canadian Patent No. 2,645,810 on March 15, 2027. The Court rejected Amgen’s anticipation and obviousness defences.
Further trials involving the same patent against Samsung Bioepis (regarding its biosimilar EPYSQLI) were scheduled for July 2025, and a separate patent trial between Alexion and both Amgen and Samsung Bioepis was scheduled to begin in November 2025.
Aflibercept (EYLEA) – Bayer/Regeneron v. Amgen and Sandoz
Patent infringement actions brought by Bayer and Regeneron against Amgen relating to Amgen’s ABP938 (a biosimilar of EYLEA) proceeded to trial in May and June 2025. A decision remains under reserve. Additional patent trials involving different patents were scheduled for August 2025. Ongoing actions against Sandoz relating to its aflibercept biosimilar AFQLIR have a first trial scheduled for October 2026.
Ustekinumab (STELARA) – Samsung Bioepis v. Janssen
Samsung Bioepis commenced an action seeking to invalidate Janssen’s patent relating to ustekinumab in connection with its biosimilar PYZCHIVA. Janssen’s motion for leave to counterclaim for infringement, filed after PYZCHIVA was granted a Notice of Compliance, was dismissed for being insufficiently particularised (Samsung Bioepis v. Janssen, 2024 FC 1715).
The Evolving Doctrine of Inducing Infringement
Recent Federal Court of Appeal decisions have clarified, and arguably strengthened, the doctrine of inducing infringement in ways that are particularly relevant to biosimilar manufacturers.
The Three-Part Test
Canadian law recognises that a patent may be infringed not only by someone who directly makes, uses, or sells the claimed invention, but also by someone who induces another to infringe. The test for inducing infringement, established in Corlac Inc. v. Weatherford Canada Inc., 2011 FCA 228, requires: (1) direct infringement by a third party; (2) the alleged inducer influenced the third party to the point that, without such influence, infringement would not have occurred; and (3) the alleged inducer knew that its actions would result in infringement.
Key 2024 Federal Court of Appeal Decisions
In 2024, the Federal Court of Appeal issued several decisions that clarified the “influence” requirement in the context of product monographs and dosage regimen patents:
Janssen Inc. v. Teva Canada Limited, 2023 FCA 68: The Court of Appeal held that a generic manufacturer’s product monograph can be sufficient to establish infringement by inducement. Critically, it is irrelevant whether prescribing physicians were actually influenced by the product monograph, all that is required is that the monograph provided instructions that, when followed, would result in infringement of the claimed dosing regimen.
Apotex Inc. v. Janssen Inc., 2024 FCA 9: Apotex argued that because its product monograph was essentially a copy of Janssen’s monograph for INVEGA SUSTENNA, prescribing practices would not change. The Court dismissed this argument, stating that it incorrectly implied a requirement that prescribing practices be altered. The ultimate act of direct infringement could be by either a prescriber or a patient.
Pharmascience Inc. v. Janssen Inc., 2024 FCA 10: Pharmascience argued that because it did not offer a 75 mg dose (an essential element of each patent claim), any 75 mg dose would be sourced from Janssen, creating an implied licence. The Court rejected this, holding there was no reason to conclude that Janssen’s sale of a component would constitute a licence to use the entire claimed dosage regimen.
The Supreme Court of Canada denied leave to appeal in each of these cases, leaving the Federal Court of Appeal’s rulings as the current state of the law. The practical effect: dosage regimen patents have become more challenging for biosimilar manufacturers to design around.
Provincial Biosimilar Switching Policies
Beyond patent litigation, commercial success for biosimilars depends on provincial reimbursement policies. As of August 2024, every Canadian province has implemented some form of biosimilar switching policy requiring patients receiving public funding for certain reference biologic drugs to transition to biosimilar versions (subject to case-by-case exceptions).
Manitoba was the last province to implement such a policy, with its Biosimilar Initiative taking effect on August 1, 2024. These policies have had a significant impact: biosimilars of filgrastim and pegfilgrastim now hold 94.5% and 99.9% market share of prescriptions for those molecules, respectively, while market shares for other biosimilars range from 0.9% (insulin aspart) to 74.9% (rituximab), according to data from the Patented Medicine Prices Review Board.
As of mid-2025, 68 biosimilars have been approved in Canada for 21 innovator reference products. The combination of accelerated regulatory pathways and provincial switching policies creates strong commercial incentives for biosimilar market entry, and correspondingly strong incentives for innovators to enforce their patent rights.
What This Means for Your Business
For Innovator Pharmaceutical Companies
Prepare for earlier litigation timelines. If Health Canada finalises the draft guidance, biosimilar submissions could arrive 12-18 months earlier than previously anticipated. Patent litigation strategies, including expert witness identification and claim chart preparation, should be advanced accordingly.
Evaluate patent portfolio coverage. With the Federal Court of Appeal’s clarifications on inducing infringement, dosage regimen patents remain valuable enforcement tools. Ensure that patents are properly listed on the Patent Register and that product monograph language is monitored for potential inducement.
Monitor international developments. Similar regulatory changes in the EU, UK, and US may provide early indicators of litigation strategies and outcomes that could inform Canadian proceedings.
For Biosimilar Manufacturers
Accelerate commercial planning. Faster regulatory pathways create opportunities for earlier market entry, but only if patent clearance strategies keep pace. Conduct freedom-to-operate analyses early and identify potential patent risks before filing regulatory submissions.
Carefully draft product monographs. Given the Federal Court of Appeal’s inducing infringement jurisprudence, product monograph language is a critical risk factor. Consider whether dosing instructions can be drafted to avoid triggering patent claims without compromising regulatory compliance.
Budget for litigation. While settlement rates remain high, contested PMNOC proceedings are resource-intensive. Factor litigation costs and potential delays into commercial projections.
Looking Ahead: The Supreme Court’s Pending Decision
The biosimilar litigation landscape may shift further depending on the outcome of Pharmascience Inc. v. Janssen Inc. (SCC File No. 41209), argued before the Supreme Court of Canada on October 9, 2025. That case addresses whether methods of medical treatment, specifically, dosage regimens, are patentable in Canada.
If the Supreme Court narrows or eliminates the patentability of methods of medical treatment, it would reduce one category of patent protection available to innovators. Conversely, a decision affirming patentability would strengthen innovators’ ability to enforce dosage regimen patents against biosimilar and generic competitors.
Whatever the outcome, the convergence of regulatory acceleration and evolving patent jurisprudence means that biosimilar patent disputes will remain a high-stakes area of Canadian intellectual property litigation for the foreseeable future.
Conclusion
Health Canada’s proposed guidance to eliminate phase 3 clinical trial requirements for biosimilars represents a pivotal shift in Canadian pharmaceutical regulation. For businesses operating in the biologics space, the implications extend far beyond regulatory compliance, they reshape litigation timelines, commercial strategies, and the value of patent portfolios.
The coming wave of biosimilar disputes will require sophisticated legal strategies that integrate regulatory planning, patent enforcement (or challenge), and commercial objectives. Companies that prepare now, by evaluating their patent positions, monitoring regulatory developments, and engaging experienced litigation counsel, will be best positioned to navigate this evolving landscape.
Whether you are an innovator protecting your investment in biologic drug development or a biosimilar manufacturer seeking efficient market entry, the stakes are significant, and the time to prepare is now.
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