Skill, judgment, and the syringe: Pharmascience v Janssen at the Supreme Court

In the first patent case before the Supreme Court of Canada (“SCC”) since 2022, the SCC has dismissed Pharmascience’s appeal in Pharmascience v Janssen, 2026 SCC 26 and upheld Janssen’s Canadian Patent No. 2,655,335 (the 335 Patent) relating to INVEGA SUSTENNA.

The SCC dealt with a single issue: the patentability of claims directed to use of a pharmaceutical compound or formulation for the treatment of a disease according to a particular dosing regimen. The SCC upheld the conclusion of the lower courts that the patent’s claims were not directed to a method of medical treatment and provided guidance on the legal test to apply for such an analysis.

This decision is now the leading authority in Canada on patentability of methods of medical treatment.

Methods of medical treatment: Road to the SCC

The patent at issue concerns novel and inventive dosing regimens found in Janssen’s Canadian Patent No. 2,655,335 (the 335 Patent) that cover to Janssen’s INVEGA SUSTENNA product.

At trial,[1] Pharmascience argued that the following claims should be found invalid for being methods of medical treatment:

1. Claims 1 to 16 relate to prefilled syringes adapted for administration according to the claimed dosing regimens.
2. Claims 17 to 32 relate to a use of a "dosage form" according to the claimed dosing regimens.
3. Claims 33 to 48 relate to use of paliperidone as paliperidone palmitate in the manufacture/preparation of a "medicament" adapted for administration according to the claimed dosing regimen.
4. Claims 49 to 63 relate to a "dosage form" adapted for administration according to the claimed dosage regimens.

The Federal Court found that claims 1-16 (directed to the product of pre-filled syringes), claims 33-48 (directed to the manufacture of a dosage form), and claims 49-63 (directed to a dosage form) as vendible products were valid and did not further analyze them as potential methods of medical treatment.

The Federal Court’s analysis focused on claims 17-32, which were directed to the use of the dosage form. Manson J. found the claims valid, finding that the claimed dosage regimen did not engage a physician’s skill in judgment as all the physician had to do was choose whether or not to use the dosage regimen.

The Federal Court of Appeal upheld the decision. After reviewing the jurisprudence, the Court of Appeal opined that methods of medical treatment are not an "invention" as contemplated under section 2 of the Patent Act, reasoning that methods of medical treatment do not relate to trade, industry and commerce, but rather relate to non-economic professional skills and are unpatentable.[2] The FCA held that:

[37] To summarize, whether or not a patent claim to a dosing regimen relates to a method of medical treatment cannot be based exclusively on whether its dosing and schedule is fixed or not. The proper inquiry remains whether use of the invention (i.e., how to use it, not whether to use it) requires the exercise of skill and judgment, and the burden remains on the party challenging the patent. It is difficult to provide more detailed guidance than this for parties involved in future litigation and courts faced with allegations of invalidity of patent claims due to unpatentable subject matter, namely methods of medical treatment. Such allegations will generally turn on the particulars of the case and the evidence on the record.

However, the Court of Appeal agreed that the claimed dosage regimen did not require the exercise of skill and judgment in application.

SCC Decision: Majority and minority decisions

The SCC unanimously held that the claims of the patent at issue were not directed to a method of medical treatment. However, the majority and minority disagreed on how to get to that conclusion.

The majority decision

The majority held that methods of medical treatment are not patentable, but that the claims at issue were not methods of medical treatment. The majority stated that the law has long held that professional skills, of which methods of medical treatment are a subset, are not patentable subject matter under s. 2 of the Patent Act. The majority found that the distinction lies in the fact that unpatentable professional skills are distinguished from patentable innovation in trade, industry or commerce.[3]

The majority adopted the FCA’s approach in determining whether a claim is directed to a method of medical treatment.[4] The ultimate question asks if the subject matter amounts to professional medical skill and judgment, i.e., whether the invention seeks to fence in an area of medical treatment. [5]

The majority stated that this inquiry is factually suffused and evidence-based.[6] Based on the jurisprudence, the majority offered three points of guidance to assist in the inquiry:

1. “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.”[7]
2. “The more the practice of a claimed invention involves tailoring it to the circumstances of a particular patient, the more likely it is that its subject matter amounts to professional medical skill and judgment. 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.”[8]
3. “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.”[9]

The majority rejected both Pharmascience’s test: skill and judgment are engaged when a physician must determine “how and when” a drug should be administered, and Janssen’s test on whether the claims are economic in nature and patentable.[10]

As noted, the majority found that Janssen’s 335 Patent does claim patentable subject matter. The majority agreed with the FCA’s finding that once the decision to implement the dosing regimens of the 335 Patent was made, a physician’s skill and judgment were not required.[11] The majority agreed with the trial judge’s findings that (i) different dosage regimens based on differing kidney function did not tread on skill and judgment and (ii) clinically insignificant variability in the dosing regimen (e.g. ±2 days to allow for missed dose with no expected clinical difference) also did not tread on skill and judgment.

The minority decision

The two-judge minority arrived at this same result in a different way. The minority would abolish the doctrine of “methods of medical treatment” and instead have patentability assessments follow the statutory definition of “invention” under s.2 of the Patent Act.

The majority and minority reasons are each lengthy and demonstrate an interesting legal debate amongst the Court on the issue of whether methods of medical treatment ought to be patentable.

Takeaways for the future

Overall, the majority’s decision continues the current jurisprudence of the Federal Court and Federal Court of Appeal, and provides additional guidance.

The fact- and evidence-infused inquiry into these issues will continue and cases will be decided on a case-by-case approach. As such, clear evidence that supports the clinical efficacy of a dosing regimen within an objectively identifiable patient population (as opposed to the need for a physician to adjust the dosing on a subset or individual basis when in use) will be important in both litigation and patent prosecution contexts.

Gowling WLG’s Alex Ross and Mark Wilkie were cited by the SCC in its analysis of the patentability of methods of medical treatment.[12]

Gowling WLG’s Chris Van Barr, Erin Creber, Will Boyer and Mackenzie Jamieson were counsel of record for the physician intervenors.

For analysis or discussion of whether this new jurisprudence may impact your patents or patent applications, contact the Gowling WLG patent litigators and patent agents, or a member of our Life Sciences team, who would be pleased to discuss this decision and your patent strategy.

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