Last week, on July 17, 2026, the Supreme Court of Canada reaffirmed (7-2, Justices O’Bonsawin and Moreau concurring) that methods of medical treatment (“MMT”) remain unpatentable under Canadian law. See Pharmascience Inc. v Janssen Inc. and Janssen Pharmaceutica N.V., 2026 SCC 26.
Justice Jamal, writing for the majority, held that the prohibition against patenting MMT rests on the broad principle that professional skill and judgment are themselves not patentable subject matter, and emphasized that any patent which impermissibly seeks to monopolize professional medical skill and judgment is invalid.
On the facts of the case, Janssen’s drug dosing regimen patent was held to constitute patentable subject matter.
The Supreme Court judgment will provide some comfort to the generic pharmaceutical industry in maintaining the prohibition against patenting MMTs, but the decision did not go as far as either side had advocated for. The contours of the legal test for “skill and judgment” will undoubtedly be debated in further cases to come.
Factual context: the paliperidone palmitate patent
This case involved Janssen’s Canadian Patent No. 2,655,335 claiming a dosing regimen for paliperidone palmitate (INVEGA SUSTENNA), a drug used to treat schizophrenia. The dosing regimen was intended to address the well-recognized problem of treatment non-adherence among patients with schizophrenia and as an alternative to daily pills.
In brief, the claimed dosing regimen is for a long-acting injectable formulation, administered in two fixed loading doses followed by a fixed maintenance dose at monthly intervals. Janssen’s 335 patent contained both “product” and “use” claims, all incorporating the dosing regimen.
Pharmascience sought regulatory approval to market a generic version of paliperidone palmitate. Both the Federal Court and Federal Court of Appeal upheld the validity of Janssen’s patent and found that Pharmascience would infringe the patent, thereby preventing Pharmascience from obtaining regulatory approval until expiry of the patent.
On the issue of MMT, the lower courts held that the 335 patent did not claim an MMT because the claims are directed at a “commercial offering”, and that using the invention does not require physicians to exercise their skill and judgment.
Pharmascience appealed on the basis that the lower courts’ MMT analysis was too permissive, arguing that a properly defined test for MMT should have invalidated the patent. Janssen, for its part, did not simply defend the result below – it went further to say that there should not be any prohibition on patenting MMT, overturning decades of precedent.
Legal context: prohibition against methods of medical treatment
MMTs have been unpatentable in Canada for many decades, at least since the Supreme Court of Canada’s decision in Tennessee Eastman Co. v. Commissioner of Patents, [1974] SCR 111, which was based on s. 41(1) of the Patent Act (as it then was) expressly prohibiting patents for food or medicine per se except when limited to product-by-process claims.
While that provision was repealed in 1993, Tennessee Eastman had been treated as binding law in Canada absent further comment from the Supreme Court. Many parties in the pharmaceutical industry and patent practitioners had argued for years that Tennessee Eastman was no longer good law, and advocated revisiting or abolishing the prohibition against MMT patents, depending on their side. For this reason, the Supreme Court’s decision in this case was heavily anticipated by the pharmaceutical industry.
The Holding: SCC holds that MMT is a proper ground of invalidity
In its decision, the Supreme Court not only reaffirmed the prohibition against MMTs but fundamentally reframed its legal foundation. Rather than being based on the now-repealed s. 41(1), the majority held that the unpatentability of MMTs is grounded in the public policy rationale prohibiting the monopolization of professional skills.
The Court weighed the benefits of prohibiting MMT patents in a detailed analysis of the history and context surrounding the doctrine. The Court drew heavily from the “patent bargain”, balancing the incentive for research and development, public disclosure, and the grant of monopoly rights.
According to the majority, granting patents on medical skills would not achieve the purposes of innovation and public disclosure in the Patent Act because physicians are already required by their ethical obligations to exercise their skill and judgment in the best interests of their patients and to share their knowledge with others.
The Court also emphasized that the patent system is not intended to regulate how professionals exercise their skill and judgment; physicians already enjoy a state-granted professional monopoly to practice medicine – granting patent monopolies over medical skills would do little to advance the purposes of the Patent Act.
The Test: A slightly revised test for methods of medical treatment?
In affirming that MMTs are unpatentable, the majority set out a test: a claim is invalid “if it seeks to monopolize professional medical skill and judgment”. Although the Supreme Court agreed with the general formulation and application of the test stated by the lower courts (focusing on “whether use of the invention requires the exercise of skill and judgment”), the wording and emphasis on monopolization, rather than presence of skill and judgment, are somewhat different.
Whether something is a method of medical treatment will be a factually driven inquiry which focuses on the substance of the claim as construed, above its form. The SCC provided three examples of relevant non-exhaustive considerations:
- The proper question is whether the subject matter of the claimed invention amounts to professional medical skill and judgment, not whether skill and judgment would be applied in deciding whether to use the claimed invention.
- The more that the claimed invention employs personalization to meet the unique needs of a patient, the more likely it is that the claim amounts to an attempt to monopolize professional medical skill and judgment. In the context of dosing regimens, this might include consideration of whether the dosing regimen is fixed or variable.
- The more a medical professional would already be incentivized to develop or improve a given subject matter in the course of their professional practice, the more likely it is that the subject matter amounts to a method of medical treatment.
The Outcome: Janssen’s 335 patent remains valid
Applying this framework to Janssen’s 335 patent, the Court held that it does not claim an unpatentable MMT because medical skill and judgment are not required to implement the claimed dosing regimen: the dosing schedule for patients with and without impaired kidney function is fixed and objective, and the permitted variation in dosing windows and maintenance injection site had no clinical significance.
Concurring reasons would have abolished MMT prohibition
In concurring reasons, Justices O’Bonsawin and Moreau would have done away with a blanket MMT prohibition entirely, remarking that the existing doctrine is both conceptually unstable and practically unworkable. In their view, other existing grounds of invalidity properly deal with concerns over patenting MMTs.
Rather than asking whether a claim amounts to professional skill and judgment as a threshold subject-matter question, they would have folded that inquiry into the utility requirement: in their view, a patent dependent on a physician’s subjective judgment would likely be invalid for lack of utility because it would lack operability, reproducibility or control.
As the majority noted, it is not clear whether the concurring judges sought to alter the existing utility standard, or whether the usual “scintilla” would apply.
Takeaways
The Supreme Court majority approach affirmed that MMTs are unpatentable and that this prohibition is an independent basis of invalidity operating ahead of other invalidity doctrines including novelty, obviousness, and utility.
Ultimately, while Pharmascience lost on the result due to the Court’s view of the facts and Janssen’s 335 patent, the Court left the door open for additional challenges to medical treatment patents and in that sense may be considered positive for future generic pharmaceutical entrants.
On the other hand, the Court’s revised formulation of the MMT test (focusing on the monopolization of medical skill and judgment, rather than asking whether skill and judgment is required to use the invention) appears on its face to reflect a somewhat narrower scope of invalidity.
In any event, the Court left the boundaries of the “skill and judgment” inquiry to be worked out on a case-by-case basis, leaving some open questions to be answered in future disputes. Some interesting open questions include:
- The future role of the “fixed versus variable” distinction: While fixed dosing regimens have historically been viewed as patentable, the Court emphasized that this distinction is merely evidentiary and never determinative. Future cases will likely explore how much weight courts should give to that factor and whether similar considerations apply to treatment plans more broadly.
- The limits of permissible physician discretion: The Court confirmed that some patient-specific treatment decisions can remain patentable. The question will be where that line is – how much can a claim include until it impermissibly interferes with a physician’s skill and judgment?
- Whether the professional skills principles extend beyond physicians: The majority repeatedly grounded its reasoning in the broader prohibition against patenting professional skills, expressly detaching the doctrine from now-repealed statutory provisions relating to methods of medical treatment. As a result, the Court may have opened the door to future arguments involving other regulated professions that exercise skill and judgment, such as engineering.
While Janssen’s dosing regimen patent survived this particular challenge, the prohibition against patenting MMTs emerges on a stronger doctrinal footing. Generic drug manufacturers retain an important tool to challenge patents that attempt to monopolize the practice of medicine. How the skill and judgment test will be applied to the next generation of dosing regimen and treatment-protocol patents is likely to remain a focus of patent challenges in the pharmaceutical sector.