Gillian Burrell

Pharmascience Inc. v. Janssen Inc., 2026 SCC 26

The Supreme Court of Canada’s(“SCC”) recent judgment on the patentability of methods of medical treatment is most notable for what it doesn’t do. The decision doesn’t alter the law and declare methods of medical treatment to be patentable in Canada. It doesn’t clearly alter the scope of what does or does not constitute an unpatentable method of medical treatment. It doesn’t overturn the Federal Court (“FC”) and Federal Court of Appeal’s (“FCA”) findings that Janssen Inc.’s (“Janssen”) patent is valid or their dismissal of Pharmascience Inc.’s (“Pharmascience”) claims. Instead, after nearly six years of litigation and a series of related cases, motions, and procedural disputes surrounding the validity of Janssen’s patent, the SCC, in a 7-2 decision, decided to (mostly) maintain the status quo.

Background

Janssen owns Canadian Patent No. 2,655,335, which covers dosing regimens for INVEGA SUSTENNA, a long-acting injectable formulation of paliperidone palmitate used to treat schizophrenia.[i] The patent includes “product claims” for pre-filled syringes at specified levels (50 mg, 75 mg, 100 mg, and 150 mg) along with “use claims” for the administration of the drug according to a specific dosing regimen and schedule.[ii]

Pharmascience wanted to market a generic version and argued that Janssen’s patent was invalid because it claimed an unpatentable method of medical treatment. Specifically, Pharmascience alleged that the claimed treatment schedule, with particular timelines and dosage amounts, relied on a physician’s skill and judgment.

At trial, the FC rejected Pharmascience’s arguments and concluded that Janssen’s patent was not a method of medical treatment, as the product claims were directed to vendible products and the use claims did not require the exercise of professional skill and judgment. The FCA upheld that decision, and Pharmascience appealed to the SCC, as reported in our previous post.

At the SCC, Pharmascience argued that the test for determining whether a pharmaceutical treatment was an unpatentable method of medical treatment should be broadened to include any dosing regimen that describes when and how medicine is to be administered. The SCC rejected this argument, finding that the proper focus is on whether the patent claims the professional skill and judgment of the medical profession.[iii]

For its part, Janssen argued that the SCC should overturn decades of precedent and find that methods of medical treatment are, in fact, broadly patentable. Janssen’s argument drew attention to the fact that case law establishing the unpatentability of methods of medical treatment could be traced back to a 1971 SCC decision that relied on a since-repealed provision of the Patent Act.[iv]

The SCC also rejected this counterargument. The majority determined that the unpatentability of methods of medical treatment is a self-supporting principle that Parliament did not intend to undo when the provision was repealed.[v]

What, Exactly, Is a Method of Medical Treatment?

In maintaining the status quo, the SCC clarified the test for determining whether the claimed subject matter constitutes an unpatentable method of medical treatment. In short, the majority reiterated that the use of professional skill and judgment in determining whether to administer a specific treatment should not be the focus of the analysis. Instead, the question is whether the subject matter of the claimed invention amounts to professional skill and judgment.[vi] The majority pointed to two additional factors to 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; and
• 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.[vii]

Notably, the majority explicitly rejected the notion that distinguishing “fixed” from “variable” dosing regimens was determinative as to whether a dosing regimen was or was not patentable.

The Concurring Judges Would Have Gone Further

Two judges of the SCC agreed that Janssen’s patent was valid, but they would have changed the law more dramatically than the majority opinion. In their view, methods of medical treatment should be treated as patentable subject matter. Instead of rejecting claims that rely on professional skill and judgment as inherently unpatentable, such claims would instead sink or swim under the utility doctrine.[viii]

In the opinion of the concurring judges, patents that rely on the professional skill and judgment of medical practitioners may fail to show the requisite utility required for patentability because the results would lack reproducibility when carried out by different practitioners.[ix]

For now, however, such a broad departure from precedent is not in the cards.

Commentary: Stability and, Perhaps, Clarity

For pharmaceutical companies, biotechnology startups, and medical device businesses, this decision provides useful stability. Canada’s Supreme Court has confirmed that patents for variable dosage regimes can still be valid.

While the SCC refrained from establishing bright-line rules, it provides some guideposts on how to draft claims covering the use of a specific treatment or dosing schedule. These claims should be phrased to ensure they do not amount to professional medical skill and judgment. Reference to the factors set out in the majority judgment, such as whether the treatment must be individualized for a given patient or whether the treatment would be improved or developed by professionals in the ordinary course, will be key in drafting such claims.

The decision may also have implications for personalized medicine, where treatment decisions are increasingly tailored to individual patients based on genetic, biomarker, or other patient-specific information.

For more information about pharmaceutical patents, dosing regimen patents, or life sciences IP strategy, please contact Ashley Chu and Gillian Burrell at PCK Intellectual Property.

[i] Pharmascience Inc. v. Janssen Inc., 2026 SCC 26 [“SCC Decision”].
[ii] SCC Decision at paras. 13-14.
[iii] SCC Decision at para. 82.
[iv] Tennessee Eastman Co. v. Commissioner of Patents, [1974] S.C.R. 111, relying on the former s. 41(1) of the Patent Act.
[v] SCC Decision at paras. 76-79.
[vi] SCC Decision at para. 93.
[vii] SCC Decision at para. 100.
[viii] SCC Decision at para. 129.
[ix] SCC Decision at para. 281.