Executive Summary: Key Legal and Evidentiary Issues

• The appeal turned on whether methods of medical treatment are patentable subject matter under section 2 of the Patent Act, R.S.C. 1985, c. P-4.
   
• Pharmascience argued that Janssen's patent for a paliperidone palmitate dosing regimen improperly claims an unpatentable method of medical treatment.
   
• Janssen argued that the 1993 repeal of former section 41(1) removed the statutory foundation for treating methods of medical treatment as unpatentable.
   
• Seven judges reaffirmed the long-standing rule against patenting methods of medical treatment while clarifying when a claim crosses that line.
   
• A separate set of concurring reasons by two judges would have discarded that rule entirely, holding that methods of medical treatment are not categorically excluded from patentability.
   
• Both sets of reasons agreed that the 335 Patent does not claim an unpatentable method of medical treatment, resulting in dismissal of the appeal.
   

Facts of the case

Schizophrenia affects over 300,000 Canadians and requires lifelong management with antipsychotic medication, but non-adherence is common and often triggers relapse. Long-acting injectable formulations, or "depot formulations," can improve adherence by releasing medication gradually and reducing the need for daily oral dosing. Beginning in the early 1990s, Janssen Inc. and Janssen Pharmaceutica N.V. (together, "Janssen") developed a long-acting injectable formulation and dosing regimen for paliperidone, the active antipsychotic molecule in paliperidone palmitate, to treat schizophrenia. Janssen conducted phased clinical studies over roughly two decades, including two large Phase III trials involving over 850 patients between 2004 and 2006, before arriving at the dosing regimen underlying its patent.

Janssen filed a Canadian patent application on December 17, 2008, and Patent 2,655,335 (the "335 Patent") issued on September 6, 2016. The 335 Patent teaches a first dose administered in the deltoid muscle on Day 1, a second dose in the deltoid muscle on Day 8 (plus or minus two days), and subsequent monthly doses in either the deltoid or gluteal muscle (plus or minus seven days). Patients without impaired kidney function receive 150 and 100 mg-eq. for the first two doses and 75 mg-eq. monthly thereafter; patients with impaired kidney function receive 100 and 75 mg-eq. for the first two doses and 50 mg-eq. monthly thereafter. Janssen markets the formulation as INVEGA SUSTENNA. The patent contains 63 claims: some are "use claims" tied to a delivery system (claims 17-32), and the remainder are "product claims" covering prefilled syringes, drug preparations, and delivery systems adapted to the dosing regimens (claims 1-16 and 33-63).

Pharmascience Inc. sought approval to market a generic version of INVEGA SUSTENNA, called pms-PALIPERIDONE PALMITATE, which led to separate infringement and validity proceedings before the Federal Court. Both the Federal Court and the Federal Court of Appeal held that Pharmascience's generic product would infringe the 335 Patent, and infringement was not before the Supreme Court. On validity, the Federal Court rejected Pharmascience's arguments that the 335 Patent's claims are obvious and that they claim an unpatentable method of medical treatment; only the latter ground was pursued on appeal. The trial judge found that the product claims are patentable "vendible product" claims, and that the use claims require no professional skill or judgment because the dosage amounts, intervals, and injection sites are fixed, with the limited variability in dosing windows and injection site having no clinical implications. The Federal Court of Appeal dismissed Pharmascience's appeal, agreeing that a claim may concern a vendible product even where a dosing regimen is an essential element, and that Pharmascience had not shown any reviewable error in the trial judge's findings. Pharmascience then appealed to the Supreme Court of Canada on the sole remaining issue of unpatentable subject matter.

Policy and legislative provisions at issue

The central provision is section 2 of the Patent Act, which defines a patentable "invention" as "any new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter." Also at issue was the historical role of former section 41(1) (later section 39(1)) of the Patent Act, which restricted the patenting of substances intended for food or medicine except when produced by particular processes, and which was repealed in 1993. The Court's 1974 decision in Tennessee Eastman Co. v. Commissioner of Patents was grounded partly in that provision and established that methods of medical treatment are unpatentable. The parties also invoked Article 27(3)(a) of the TRIPS Agreement, which permits, but does not require, member states to exclude "diagnostic, therapeutic and surgical methods for the treatment of humans" from patentability. Pharmascience urged the Court to broaden the test for identifying an unpatentable method of medical treatment; Janssen urged the Court to hold that methods of medical treatment are no longer excluded from patentability at all following the repeal of section 41(1).

Reasoning and analysis

Writing for seven judges (Wagner C.J. and Karakatsanis, Côté, Rowe, Martin, Kasirer and Jamal JJ.), Jamal J. held that methods of medical treatment remain unpatentable because they reflect the broader principle that professional skills unrelated to trade, industry, or commerce are not proper subject matter for a patent. A purposive reading of section 2 supports this conclusion: the Patent Act is designed to incentivize inventiveness through a temporary monopoly in exchange for public disclosure, and physicians already hold a state-granted monopoly to practise medicine and are under ethical obligations to use their skills for patients' benefit, so they need no patent incentive to do so. The majority found nothing in the legislative history of the 1993 repeal, or in Canada's response to the TRIPS Agreement, to suggest Parliament intended to disturb the settled rule from Tennessee Eastman, noting that a substantial and unbroken line of Federal Court and Federal Court of Appeal decisions has continued to treat methods of medical treatment as unpatentable since the repeal.

The majority went on to hold that a patent impermissibly claims a method of medical treatment only where it seeks to monopolize professional medical skill and judgment, assessed by construing the claims purposively and focusing on substance over form. It identified three non-exhaustive guiding considerations: whether the claimed invention itself amounts to professional skill and judgment (rather than whether such skill would be used in selecting the invention for a patient); whether the subject matter requires tailoring to individual patients, which points toward an unpatentable method; and whether a medical professional would already be incentivized to develop the subject matter in the ordinary course of practice. The majority rejected a bright-line rule based solely on whether a dosing regimen is fixed or variable, treating that distinction as a useful but non-dispositive evidentiary proxy. Applying these principles, the majority found no reviewable error in the trial judge's findings that the 335 Patent's dosage amounts, intervals, and injection sites are fixed or clinically interchangeable, and that no physician skill or judgment restricting treatment decisions is required. On that basis, the 335 Patent does not claim an unpatentable method of medical treatment.

In joint concurring reasons, O'Bonsawin and Moreau JJ. agreed the appeal should be dismissed but reasoned differently, concluding that Tennessee Eastman should be reconsidered. In their view, its reasoning depended on a now-repealed provision, and the tests developed since then — turning on "skill and judgment" or "vendible product" status — are unworkable, lack coherence, and produce inconsistent results. Using the modern approach to statutory interpretation, they concluded that methods of medical treatment, including dosing regimens, are not categorically excluded from patentable subject matter and instead should be assessed under the Patent Act's ordinary requirements of novelty, utility, and non-obviousness, with the utility criterion in particular filtering out claims that depend on a physician's unreproducible skill and judgment. They emphasized that this approach does not open the door to patenting all methods of medical treatment. Novelty and utility were not in dispute before the Federal Court, and the concurring judges saw no basis to disturb the trial judge's finding that the patent is otherwise valid because it is non-obvious and falls within patentable subject matter, concluding that the 335 Patent is valid.

Ruling and overall outcome

The Supreme Court of Canada dismissed Pharmascience's appeal, with both the majority and the concurring judges agreeing that the 335 Patent is valid and that Janssen was the successful party, though they reached that result by different legal routes: the majority by holding that the patent does not claim an unpatentable method of medical treatment, and the concurring judges by holding that methods of medical treatment are not categorically unpatentable at all. On costs, the source materials are inconsistent: the majority reasons state that, because the Court rejected the principal positions of both parties, no costs would be awarded to either side [Jamal J., para. 124], while the joint concurring reasons state that costs should be awarded to Janssen [O'Bonsawin and Moreau JJ., para. 285]; the decision's final disposition line, however, records that the "[a]ppeal [is] dismissed without costs." No other monetary award, damages, or costs figure is specified in the decision.