Supreme Court Of Canada: Methods Of Medical Treatment Unpatentable, Validity Of Janssen’s Paliperidone Dosing Regimen Patent Upheld

Today the Supreme Court of Canada released its decision in Pharmascience Inc v Janssen Inc, 2026 SCC 26 on the patentability of methods of medical treatment, dismissing Pharmascience’s appeal.

The sole issue on appeal was whether Janssen’s Canadian Patent No 2,655,335 (the 335 Patent) relating to paliperidone palmitate (INVEGA SUSTENNA) is invalid for claiming an unpatentable method of medical treatment. The claims at issue include the features of a paliperidone palmitate formulation dosing regimen for treatment of schizophrenia.

As previously reported, the Federal Court of Appeal had affirmed the finding of the Federal Court that the claims were not unpatentable methods of medical treatment, holding that the proper inquiry for such claims is “whether use of the invention (i.e., how to use it, not whether to use it) requires the exercise of skill and judgment”.

Justice Jamal delivered the majority decision, affirming that methods of medical treatment are not patentable subject matter in Canada but upholding the findings of the Federal Court that the 335 Patent claims patentable subject matter. The minority judgment delivered by O’Bonsawin would have overruled the prior jurisprudence that methods of medical treatment are unpatentable.

Approach to determination of whether claims are directed to unpatentable methods of medical treatment

The majority’s assessment of the test for whether a claim is an unpatentable method of medical treatment is found at paragraphs 88-100 of the decision. The majority held that the first step in analyzing the claimed subject matter is to construe the claim purposively, emphasizing substance over form, i.e., regardless of how the claim is drafted. The analysis set out by the majority focused on the involvement of professional medical skill and judgment in practising the claimed invention and recommended the following three non-exhaustive points of guidance in this determination.

First, the analysis should focus on whether the subject matter of the claimed invention amounts to professional medical skill and judgment, not whether professional medical skill and judgment would be applied in selecting the claimed invention for a particular patient or use. In addition, the majority counselled that one should avoid confusing the professional medical skill and judgment exercised in monitoring a patient to decide whether a claimed invention remains appropriate with the claimed invention itself. In other words, the need for professional skill and judgment in determining whether the subject matter is or continues to be an appropriate treatment option for a particular patient will generally not affect its patentability.

Second, the degree of tailoring to specific patients should be considered - the more the subject matter involves tailoring treatment to individual patients, the more likely it is that it amounts to a method of medical treatment. By contrast, where the subject matter of the claimed invention can be applied generally to a broad class of patients without individual adjustment, it is less likely to be a method of medical treatment. The majority, however, recognized that there is not a bright line between subject matter that is individualized and subject matter that is not.

Third, the majority stressed that the application of the test must remain focused on the purpose of the rule that methods of medical treatment are unpatentable subject matter, reasoning that these need not be incentivized through the patent bargain because medical professionals are expected to innovate within their areas of practice. The more a medical professional would be able to develop or improve the subject matter in the ordinary course of treating patients, the more likely it is that the subject matter constitutes a method of medical treatment.

The majority continued:

[98] This Court’s jurisprudence illustrates how the above points of guidance apply in concrete circumstances. In Tennessee Eastman, the unpatentable claims described “a surgical method for joining or bonding the surfaces of incisions or wounds in living animal tissue” by applying an already well-known adhesive compound (p. 112). That method would have to be adapted to each patient and each potential use of the compound, depending on, for example, the nature of the incision, wound, and tissue. Professional medical skill and judgment would be engaged not just in choosing to follow this method but also in applying it to treat a patient. By contrast, in Wellcome, the patentable claims were for the use of AZT to treat HIV/AIDS. Professional medical skill and judgment would be engaged in deciding whether to prescribe AZT to a patient for this purpose based on their individual medical circumstances, but much less so in the actual use of AZT to treat HIV/AIDS [at para. 83 of its reasons, the majority referenced the claims which included a unit dose of 10 to 1500 mg of AZT]. The claimed invention was not the kind of innovation that a medical professional would be expected to develop and refine in treating individual patients within their practice, but instead was “a commercial offering” (para. 50).

The majority noted that each case involving methods of medical treatment ultimately will depend on the particular facts and the jurisprudence of the Federal Court.

Application to the 335 Patent claiming dosing regimens 

The majority held that dosing regimens can be patentable, but a categorical distinction between fixed and variable dosing regimens is not the correct method for the analysis. Determining patentability of a dosing regimen is a factual exercise that depends on the evidence and how it will be applied. In this case, the majority upheld the findings of the Federal Court that “skill and judgment are not required to implement the claimed dosage regimens”.

Although the question of whether methods of medical treatment are patentable has now been laid to rest, the focus of future cases will continue to consider the issue of physician’s skill and judgment in practising the claimed invention.

Should you have any questions, please do not hesitate to contact a member of the Patents, Pharmaceutical Litigation or Life Sciences Regulatory & Compliance groups.