Here’s what’s happening right now.

On July 17, 2026, the Supreme Court of Canada published its highly anticipated reasons for Pharmascience Inc. v. Janssen Inc. In addition to determining the validity of Janssen’s patent, the appeal examines whether methods of medical treatment are patentable subject matter under Canada’s Patent Act (R.S.C. 1985, c. P-4), and how such methods should be defined. 

Writing for the majority, Justice Jamal confirmed methods of medical treatment are not patentable subject matter but held that Janssen’s patent did not claim such a method.

Concurring reasons by Justices O’Bonsawin and Moreau also upholds Janssen’s patent as valid; however, the concurrence disagrees with the majority that methods of medical treatment are inherently unpatentable subject matter in Canadian patent law.

Janssen’s Patent and its Judicial History 

The appeal originates from actions initiated by Janssen pursuant to subsection 6(1) of the Patented Medicines (Notice of Compliance) Regulations (SOR/93-133) after Janssen had been served with a Notice of Allegations and Detailed Statement by Pharmascience for an Abbreviated New Drug Submission (ANDS).

The ANDS sought approval to market and sell a generic version of Janssen’s INVEGA SUSTENA®, a paliperidone palmitate suspension for the treatment of schizophrenia.

The dosing regimens in the product monograph for INVEGA SUSTENNA® fall within the claims of Janssen’s Canadian Patent No. 2,655,335 (the “335 Patent”). The 335 patent addresses one of the major causes of relapses in schizophrenic patients, non-adherence to treatments, by disclosing dosing regimens for long-acting injectable paliperidone palmitate formulations. Janssen’s development of the formulation and dosing regimen began in the early 1990’s and required a series of phase studies to calibrate the optimal dosing regimen for paliperidone palmitate.

Only in 2007 did Janssen’s continued research arrive at the dosing regimen that became the basis of the 335 Patent.

At the Federal Court, Pharmascience’s invalidity arguments relating to obviousness, lack of inventiveness, and unpatentable subject matter, namely methods of medical treatment, were rejected.

Pharmascience challenged the validity of the 335 Patent on appeal solely on the latter ground. The Federal Court of Appeal dismissed Pharmascience’s appeal, holding that the patent is valid since its claims were found to not be directed to methods of medical treatment.

Writing for a unanimous court, Justice Locke reasoned that the claimed invention did not require the exercise of a physician’s skill and judgment. 

The Majority’s Reasons

Methods of Medical Treatment as Unpatentable Subject Matter: Maintaining the Status Quo

Writing for the majority, Justice Jamal, ruled that methods of medical treatment should remain unpatentable subject matter in Canadian patent law. His analysis begins with reviewing Tennessee Eastman Co. et al. v. Commissioner of Patents, [1974] SCR 11 (Tennessee Eastman), a case that has generated much debate and uncertainty on the methods of medical treatment doctrine. 

As Justice Jamal explains, the basis on which methods of medical treatment were held to be unpatentable shifted as Tennessee Eastman moved through the courts.

The patent examiner’s refusal was because the applicant claimed the use of an adhesive in a surgical process whose success depended on a physician’s skill. Accordingly, the claims were considered strictly in the medical arts and not an “invention” as defined in s. 2(d) of the Patent Act.

The patent examiner also refused the patent as it would be contrary to s. 41(1) of the Patent Act, which prohibited the patenting of a substance intended for food or medicine except when prepared or produced by particular methods or processes of manufacture.

Then, the Commissioner of Patents and Exchequer Court each dismissed the following appeals, both relying on the same ground that the patent application claimed a method of medical treatment in the field of surgery, which was neither patentable as an “art” nor “process”, and thus not an “invention” under s. 2(d) of the Patent Act. In the appeal before the Supreme Court of Canada, Justice Pigeon concluded that methods of medical treatment are not “contemplated in the definition of invention as a kind of process” and also cited s. 41(1) of the Patent Act. 

Justice Jamal then explains that the methods of medical treatment doctrine is a specific application of a broader principle, affirmed by the Supreme Court of Canada, that professional skills, which are unrelated to trade, industry, or commerce, are not patentable subject matter.

A purposive interpretation of s. 2 also confirms that methods of medical treatment are not patentable subject matter, since allowing the patenting of professional skills would not advance the purpose of the Patent Act, which is to advance innovation.

There is no need to provide professionals with the incentive of patent protection when they are already under an ethical obligation to exercise their skill and judgment in their client’s best interests. 

Furthermore, Justice Jamal advances that even after the repeal of s. 41(1), Canadian courts have continued to treat methods of medical treatment as unpatentable, including the Supreme Court of Canada in Apotex Inc. v. Wellcome Foundation Ltd., 2002 SCC 77 (Wellcome).

In Wellcome, the Supreme Court of Canada rejected the argument that a patent for the use of AZT in treating HIV/AIDS was an unpatentable method of medical treatment because the “[…] patent did not seek to ‘fence in’ an area of medical treatment”.

Additionally, Justice Jamal asserts that the repeal of s. 41(1) did not address or change the patentability of methods of medical treatment, contrary to the concurrence’s views.

In his view, nothing in the legislative debates, amendment text or contemporaneous commentary suggests the reform intended to permit the patenting of methods of medical treatment.

Lastly, Justice Jamal addresses Janssen’s claim that international law supports the view that methods of medical treatment are patentable in Canada.

Janssen’s argument was premised on the fact other jurisdictions enacted legislation excluding methods of medical treatment from patentability in response to Article 27(3)(a) of the Agreement on Trade-Related Aspects of Intellectual Property Rights, 1869 U.N.T.S. 299 (“TRIPS Agreement”), which permits signatories to exclude “diagnostic, therapeutic and surgical methods for the treatment of humans” from patentability.

In Janssen’s opinion, Canada’s omission of amendments expressly prohibiting patenting methods of medical treatment is “highly significant”.  However, Justice Jamal disagreed since it “[…] has been settled law since 1972 […] that methods of medical treatment are unpatentable in Canada”.

Overall, Justice Jamal concludes that major changes to the consistent interpretation of the Patent Act reflected in Tennessee Eastman and Wellcome should come from Parliament rather than the Supreme Court of Canada, as any changes to the law would unsettle “more than a half-century of commercial expectations built on that case law.”

A Clarified Test for Methods of Medical Treatment

Having concluded that methods of medical treatment are unpatentable subject matter, Justice Jamal set out to articulate a test for determining what constitutes unpatentable methods of medical treatment. 

Rather than adopting positions proposed by the parties, Justice Jamal opted for a “balanced approach” that is grounded in the doctrine’s purpose. In essence, to determine whether a claim’s subject matter is unpatentable as a method of medical treatment, the ultimate question is “[…] whether that subject matter amounts to professional skill and judgment [Emphasis added]”.

To answer this question, Courts should begin by construing the claims in an informed and purposeful way, based on the common knowledge of the worker skilled in the art to which the patent relates.

The analysis is then applied, regardless of how the claim is drafted, to the real subject matter of the claim. 

To supplement the test, Justice Jamal offers three points of guidance, which are not exhaustive and do not establish bright-line rules.

The first point is that the analysis should focus on whether subject matter amounts to professional medical skill and judgment, and not whether this skill and judgment is applied in selecting the claimed invention for a particular patient. Secondly, the more the practice of a claimed invention requires tailoring to the circumstances of a patient, the more likely the invention’s subject matter amounts to professional skill and judgment.

Inversely, the more a claimed invention’s subject matter can be applied to a broad class of patients without individual adjustment, the less likely it is to be a method of medical treatment.

Lastly, the test’s application must focus on the purpose of the rule that methods of medical treatment are unpatentable subject matter.

In Justice Jamal’s opinion the rule’s purpose is that methods of medical treatment do not require patent incentives because medical professionals are expected to innovate within their professional practice without such incentives.

Janssen’s 335 Patent and Dosing Regimens

Before applying the newly articulated test to the 335 Patent, Justice Jamal considered whether dosing regimens are to be considered unpatentable methods of medical treatment. In continuing with his aversion to bright-line rules, Justice Jamal held that dosing regimens are not inherently patentable or unpatentable.

He comments that categorical distinctions made between fixed and variable dosages skirt the issue of whether the claimed dosing regimens amount to professional medical skill and judgment.

The determination of a dosing regimen’s patentability is thus also a “factually suffused exercise” that will depend on the evidence.

For example, it is suggested that expert evidence could be used to contradict claimed dosages, which would suggest that the dosing regimen requires individualized adjustment and could potentially constitute a method of medical treatment.

Having confirmed that dosing regimens are to be assessed on a case-by-case basis, Justice Jamal then considers whether the 335 Patent claims methods of medical treatment. In his opinion, the trial judge correctly based his analysis on the exercise of professional medical skill and judgment by considering whether such skill and judgment is required to practice the invention as claimed.

The trial judge was also correct in supporting his conclusion with his findings, meaning his analysis was factually suffused.

For example, the trial judge found that no skill and judgment is required to implement the claimed dosing regimens after a physician has chosen a specific dosing regimen.

It was also found, based on the presented expert evidence, that the choices around dosing windows and injection sites did not have clinical implications.

Thus, the Court upheld the trial judge’s conclusion that the 335 Patent’s dosing regimens do not amount to professional skill and judgment.

Key Takeaways

In summation, the status quo was generally preserved by the Supreme Court of Canada in upholding the prohibition against methods of medical treatment as patentable subject matter.

Nonetheless, the Court clarified the doctrine’s legal test. The following points are key takeaways from the decision:

• Determining whether a claim “amounts to” professional skill and judgement, and therefore an unpatentable method of medical treatment, is a fact driven analysis. The Court declined bright-lined rules in favour of this more case-by-case approach.
• Dosing regimens are not inherently methods of medical treatment. The test must be applied to a claimed dosing regimen taking into consideration the relevant facts.
• Major changes to the Patent Act and its established interpretation are best enacted by Parliament, not the Courts.

By Chantal Prouse and Zosia Zielinski