Written By: Dr. Jennifer Raoul (Partner – Head of Life Sciences & Chemistry) & Dr. Alexander Watts (IP Lawyer)
On July 17, 2026 the Supreme Court of Canada (SCC) released its long-awaited decision in Pharmascience Inc. v. Janssen Inc., 2026 SCC 26, its most significant guidance on methods of medical treatment (MMT) in over fifty years, since it established the MMT exclusion in Tennessee Eastman Co. et al. v. Commissioner of Patents, [1974] SCR 111.
In a split 7/2 decision, the Court confirmed that MMT remain unpatentable in Canada but upheld Janssen’s dosage regimen patent and confirmed that dosage regimens are not categorically methods of medical treatment. The decision gives practitioners a governing test for patent eligibility and retires the old “fixed-versus-variable” rule, and for the first time, gives applicants of dosage regimen patents some clarity. Rather than rehash the decision here, we focus on the practical: what has been settled, and what to do now.
The governing test: professional skill and judgment
The ultimate question is now: does the claim seek to monopolize professional medical skill and judgment, effectively to “fence in” an area of medical treatment (paras. 88-89)? To assess it, the majority set out three non-exhaustive considerations (paras. 92-100):
- The focus is on whether the claimed subject matter itself amounts to skill and judgment, not whether skill and judgment are exercised in selecting the treatment for, or monitoring, a particular patient. Selection, monitoring and discontinuing treatment may sit outside the claim and do not automatically render a dosage regimen unpatentable.
- The more a regimen must be tailored to individual patients, the more likely the exclusion applies; a regimen applied generally to a broad class of patients without individual adjustment is less likely to be an MMT.
- The more a physician could develop or improve the regimen in the ordinary course of treating patients, the more likely the exclusion applies. Regimens that require clinical trials for validation are not likely to be developed in the ordinary course of physician treatment.
Because the list is expressly non-exhaustive and the inquiry is “factually suffused” (para. 106), there is no bright-line rule to follow. However, the old fixed-versus-variable test now survives only as a non-determinative “evidentiary proxy” for the degree of individualization (para. 105). A variable regimen is not inherently unpatentable, and a fixed one is not automatically patentable. The flip side is the decision’s honest limit: a regimen whose administration genuinely turns on individualized titration remains vulnerable.
Janssen illustrates the point
Canadian Patent No. 2,655,335 (“335 Patent”) claims a dosing regimen of paliperidone palmitate (INVEGA SUSTENNA) for schizophrenia: a Day 1 loading dose, a second dose at Day 8 (± 2 days), and monthly maintenance doses (± 7 days) in the deltoid or gluteal muscle, with separate amounts for patients with and without impaired renal function. On their face, those features look “variable,” but the trial judge found the dosing windows and injection-site options carry no meaningful clinical significance, and the renal-function split is an objective, binary distinction rather than an exercise of clinical judgment. Once a physician decides to use the regimen, no skill or judgment is needed to implement it, so the claims held up (paras. 119-122). The Court cautioned that a regimen is not unpatentable merely because it may not suit every patient, or because some physicians might wish to deviate from it at some point; that would be an “impossible standard” (para. 107).
Drafting tips
- Let the regimen prescribe, not the physician. A claim is strongest where the physician’s only professional role is to select the right regimen for the patient. Once that decision is made, it should not require professional skill or judgment to implement the claimed dosage regimen. Where a decision point exists, make sure the decision criteria are defined and objective, e.g. “Regimen A for creatinine clearance ≥ X; Regimen B for creatinine clearance < X” is doctrinally much cleaner than “determine renal function and select or adjust dose as clinically appropriate.”
- Build support into the specification. Where possible, provide support for workable ranges or windows and the clinical significance (or insignificance) of choices within it, whether deviation requires clinical assessment and what that assessment would be, and make subgroup assignments objective rather than discretionary.
- Treat administrative flexibility as an asset. Dosing windows and interchangeable delivery details are defensible when the record shows they exist for convenience or missed-dose tolerance rather than clinical decision-making, and that fixed points within a range are operable even if not optimal.
- Anchor sub-population distinctions to objective triggers. Tie them to objectively ascertainable criteria, so that once the criterion is satisfied the regimen follows without the clinician having to individualize it. Renal-function-based dosing survived here precisely because it was objective and binary. Avoid language that invites the examiner to read in clinical judgment.
Prosecution tips
- Push back on objections resting on variability alone. An MMT objection premised solely on a range or window is no longer well-founded; the examiner must connect the variability to professional medical skill and judgment (para. 105). Frame the question as the majority endorsed it: whether professional skill and judgment is required to practise the invention as claimed (para. 119), not whether judgment is exercised anywhere in the clinical encounter. The Court’s cautions at paras. 94 and 107 are useful ammunition against objections that a regimen is MMT just because a physician must “monitor” a patient, or because some physicians might wish to “deviate” from the regimen at some point.
- Reframe the record around the three (3) considerations. In dosing cases, the second and third usually carry the weight. The third is especially valuable: a regimen derived from population modelling, pharmacokinetic studies, and clinical trials can be characterized as research-generated technical innovation, which is distinct from a physician’s judgment in titrating an individual patient.
- Expect a transition period at the Patent Office. Patent examiners may grapple with how to apply this decision correctly to every case, and we may see objections that don’t align with the Supreme Court guidance for some time. Practitioners should familiarize themselves with the guidance and be prepared to argue directly from the decision. On a positive note, the March 2026 Practice Notice on Patentable Subject-Matter already disclaims the fixed-versus-variable test, so the governing test is not the risk; watch instead for objections that treat a physician’s judgment in selecting, monitoring or abandoning a treatment as if it defeats patentability, a point the notice does not yet capture (paras. 93-94).
What to do now
Review pending applications with dosage regimen claims, particularly any facing outstanding MMT objections. Where a claim was narrowed to a fixed dose or schedule to overcome a fixed-versus-variable objection, reassess whether broader scope, i.e. a range, a window, or a wider patient class, is now defensible on the basis that the regimen does not require individualized clinical judgment. In some files you may be able to recover scope conceded under the old framework. For applications still in prosecution, now is the time to hold the line rather than amend to the narrowest fixed form.
If you would like a review of your Canadian dosage-regimen applications in light of 2026 SCC 26, please contact the author.
This article is provided for general information only and does not constitute legal advice. For advice on your specific circumstances, please contact our IP experts today.