On July 17, 2026, the Supreme Court of Canada released its long-awaited decision in Pharmascience Inc. v. Janssen Inc., 2026 SCC 26. In a significant ruling for pharmaceutical patentees and generic manufacturers, the Court dismissed the appeal and affirmed both the continued existence of the methods-of-medical-treatment doctrine and the validity of Janssen’s patent covering dosing regimens for paliperidone palmitate (INVEGA SUSTENNA®).
Observers said the Court could revisit, or remove, the doctrine excluding methods of medical treatment from patentable subject matter. If they did so, this could affect other subject matters and industries. But the majority reaffirmed the exclusion. At the same time, the Court confirmed that dosing regimens can be patentable where they do not monopolize the exercise of professional medical skill and judgment. The reasons of the majority and the concurrence do not change much.
The Central Holding
Justice Jamal, writing for the majority, held that methods of medical treatment remain unpatentable subject matter under Canadian law because they fall within a broader principle that professional skills are not patentable. The Court stated that Canadian courts have consistently excluded methods of medical treatment from the definition of “invention” in section 2 of the Patent Act and that this exclusion remains part of Canadian patent law.
The Court expressly rejected the argument that the doctrine disappeared with the repeal of former section 41 of the Patent Act in 1993. According to the majority, the exclusion does not rest solely on the now-repealed statutory provision but also on the broader principle that professional skills are not proper subject matter for patents.
The Court explained:
this Court has continued to apply the rule that methods of medical treatment are unpatentable subject matter (Wellcome). More broadly, this Court has affirmed that professional skills are not patentable (Shell Oil; Wellcome).
The majority also endorsed the traditional policy rationale underlying the doctrine:
Medical professionals do not require the incentives of the patent bargain to exercise their skill and judgment in their patients’ best interests or to disseminate their knowledge widely.
A New Framework: Does the Claim Monopolize Professional Skill and Judgment?
Although the Court reaffirmed the exclusion, it also clarified how the doctrine should be applied.
The key question is whether a patent claim seeks to monopolize professional medical skill and judgment. The Court framed the inquiry as whether the claim seeks to “fence in” an area of medical treatment.
The majority offered several guiding principles:
- The focus is on whether the claimed subject matter itself amounts to professional medical skill and judgment.
- The fact that a physician must exercise judgment in deciding whether a treatment is appropriate for a patient does not necessarily make the claim unpatentable.
- Claims requiring individualized treatment decisions are more likely to be viewed as methods of medical treatment.
- Claims that apply generally across a class of patients with individual adjustment are less likely to be considered unpatentable (¶95).
Importantly, the Court rejected any bright-line rule based solely on whether a dosing regimen is “fixed” or “variable”. That distinction may be relevant evidence, but it is not determinative. The ultimate question remains whether the claim monopolizes professional medical skill and judgment.
Why Janssen’s Patent Survived
Applying those principles, the Court concluded that Janssen’s dosing-regimen claims did not constitute an unpatentable method of medical treatment. The trial judge had found that physicians were not required to exercise skill and judgment when implementing the claimed dosing regimens after selecting the appropriate regimen. The dosing windows and injection-site options did not have clinically meaningful implications, and the kidney-function distinctions did not improperly constrain medical decision-making.
Accordingly, the Court upheld the patent and dismissed Pharmascience’s appeal. Pharmascience thus lost at the Federal Court, the Federal Court of Appeal, and at the Supreme Court of Canada.
The Significant Concurrence
The decision was not unanimous in its reasoning.
Justices O’Bonsawin and Moreau agreed that Janssen’s patent was valid but would have gone much further. In their view, methods of medical treatment should not be treated as a distinct category of unpatentable subject matter at all. They argued that the foundations of Tennessee Eastman have largely eroded and that claimed methods of medical treatment should be assessed under the ordinary definition of “invention” in the Patent Act rather than through a separate exclusionary doctrine.
Although this position did not carry the day, the concurrence demonstrates that there remains judicial disagreement about the doctrine.
What Does This Mean for Pharmaceutical Patents?
The practical result is largely reassuring for innovators developing improved therapeutic regimens.
The Supreme Court confirmed that:
- methods of medical treatment remain unpatentable;
- dosing regimens can nevertheless be patentable;
- the relevant inquiry is whether the claims monopolize professional medical skill and judgment; and
- no bright-line distinction exists between fixed and variable dosing regimens. (¶99)
As a result, future disputes will likely focus on the degree of patient-specific tailoring reflected in the claims and whether implementation requires meaningful clinical decision-making.
Limited Impact on Computer-Implemented Inventions
Before the decision, some commentators speculated that the Court might use Pharmascience to make broader pronouncements about judicially created exclusions from patentable subject matter. Had the Court rejected the methods-of-medical-treatment doctrine altogether, that reasoning might have influenced future debates concerning computer-implemented inventions, artificial intelligence, and other contested fields.
That did not occur.
Instead, the majority reinforced the legitimacy of at least one long-standing judicially developed exclusion and grounded it in the broader principle that professional skills are not patentable. The decision is therefore unlikely to have a major direct impact on Canadian law governing computer-implemented inventions.
The judgment contains useful discussion about patentable subject matter, statutory interpretation, and the role of policy in patent law. However, its core reasoning is closely tied to medical practice and professional judgment. For that reason, its significance for software and AI patentability is likely to be modest.
However, a basis for superficial arguments. The Court says “Because professional skills do not respond to the incentives of the patent bargain, patenting them is unjustified.” Expect to see statements that because the economics of AI are completely ungrounded, the creators of systems are unmoved by the traditional patent bargain. Therefore, machine learning systems are not patent eligible. Rough arguments like this don’t fully consider all the issues.
Will these reasons by the Court be used to create new exclusions? People will try. The patent office will label human-involved steps as needing professional judgement. But the patent office tries all kinds of arguments, and so this decision won’t boost its efforts.
Bottomline
Pharmascience v. Janssen will now stand with Tennessee Eastman as a Canadian authority on methods of medical treatment and with Shell Oil and Wellcome on how professional skills are not patentable. Rather than dismantling the doctrine, the Supreme Court reaffirmed it, rooted it in the broader principle that professional skills are not patentable, and clarified that the critical inquiry is whether a claim monopolizes professional medical judgment. At the same time, the Court confirmed that properly drafted dosing-regimen claims remain capable of patent protection. The result is a conservative set of reasons and an important clarification of Canadian patent law.
Conclusion
The Supreme Court of Canada rarely hears patent cases. Indeed, this is the first subject matter case since 2004. The effect on patent eligibility could have been broad. It wasn’t. Very few applicants and patentees will be affected by this decision. If you or your company wants to protect an invention with a patent, don’t hesitate to get in touch with us.
