Supreme Court to Clarify Patentability of Methods of Medical Treatment
This article was originally published by Law360 Canada, part of LexisNexis Canada Inc.
After over a decade, the Supreme Court of Canada (SCC) will hear a pharmaceutical patent case: Pharmascience Inc. v. Janssen Inc., et al. The case concerns the patentability of methods of medical treatment, an area of law that the Courts have been grappling with for many years. The SCC is set to determine whether dosing regimens fall within the statutory definition of “invention” of the Patent Act, or remain unpatentable subject matter.
Drug Patent Litigation: A High Stakes Collision
Drug patent litigation is not an incidental by-product of the pharmaceutical industry; it is a direct and intended consequence of a carefully engineered legislative framework. It arises from a complex interplay of patent law, regulatory procedures, and economic incentives that place innovator and generic drug manufacturers on a near-inevitable collision course.
Understanding this framework is essential for navigating the strategic and procedural complexities of these high-stakes disputes. The system balance of two competing public policy goals: fostering ground-breaking pharmaceutical innovation and ensuring access to medicines.
The transition from a patented branded drug monopoly to a competitive generic market is one of the most significant and disruptive events a pharmaceutical company can face. For innovators, it represents a “patent cliff” that can erase over 80% of a drug’s revenue within a year or two of generic entry. For generics, it is a race to capture market share before commoditization erodes profitability.
The Patent at Issue and Case History
The patent infringement litigation concerns Canadian Patent No. 2,655,335 (the “335 Patent”), which teaches dosing regimens relating to INVEGA SUSTENNA® (paliperidone palmitate).
Janssen sought a declaration that Pharmascience (PMS) would infringe the 335 Patent by making, using, or selling a generic version of its patented medicine.
PMS, in response, argued that the 335 Patent was invalid because it claimed a method of medical treatment (MMT), which under Canadian law MMT is not patentable.
The 335 Patent relates to dosing regimens for long-acting injectable paliperidone palmitate formulations for treatment of schizophrenia and related disorders, and teaches a dosing regimen that ensures an optimum plasma concentration-time profile for treating patients with paliperidone.
The patent explains how paliperidone should be used and when it should be used, providing a three-part dosing regimen where different identified amounts are injected at different times.
The Federal Court (FC) found the patent to be valid and infringed. It held that:
[164] A patent claim does not patent a method of medical treatment “if it includes a specific dosage amount and/or specific administration interval”.
[…]claims restricted to particular dosages and specific administration schedules have been found to be patentable subject matter, where the amounts and timing are fixed
[…] whereas claims to dosages or schedules with ranges within which the physician must exercise skill and judgment have been found to not be a vendible product and thus not patentable[1] [emphasis added]
On appeal, PMS argued that the claims of the 335 Patent were invalid as they claimed an unpatenable MMT.
The Federal Court of Appeal (FCA) ultimately concluded that determining whether a patent impermissibly claimed a MMT was based upon the following inquiry:
[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.[2] [emphasis added]
The FCA dismissed the appeal, and PMS was granted leave to appeal to the SCC.
The Law on Patentability of Method of Medical Treatment
Canadian courts have consistently emphasized that patent law in Canada is statutory. While the Patent Act contains no explicit MMT exclusion, Courts have long grappled with whether MMTs fall within patentable subject matter.
That MMT are unpatentable dates back Tennessee Eastman, where the SCC stated:
But what of the method of medical or surgical treatment using the new substance? Can it too be claimed as an invention? In order to establish the utility of the substance this has to be defined to a certain extent. In the case of a drug, the desirable effects must be ascertained as well as the undesirable side effects. The proper doses have to be found as well as methods of administration and any counter‑indications. May these therapeutic data be claimed in themselves as a separate invention consisting in a method of treatment embodying the use of the new drug? I do not think so.[3] [emphasis added]
While the decision referred to now-repealed section 41 of the Patent Act, the FCA has affirmed that Tennessee Eastman remains authoritative. [4]
Vendible Product vs Professional Skill
Subsequent decisions held that MMT was unpatentable because it related to the exercise of skill and judgment of a physician.
The test developed and applied by the FC and FCA was whether the claim was to a “vendible product” or commercial offering which has economic value and is patentable, or whether the claim encompasses the exercise of skill and judgement of a physician which is unpatentable.[5] Courts have held that MMT claims are unpatentable because they are “essentially non-economic and unrelated to trade, industry or commerce and related rather to the area of professional skill.”[6]
Patentable subject matter has historically included:
1. use of drug X for the treatment of condition Y;
2. use of drug X for the treatment of condition Y with no dosage;
3. an effective amount of drug X to treat condition Y; and
4. fixed dosage of drug X for the treatment of condition Y.
By contrast, when it comes to dosing regimens, Courts have held that if the claim encompasses a dosage range, then it’s not patentable subject matter. Dosage regimen are unpatentable because choosing dosage regimens for patients is within physicians’ exclusive purview by virtue of their professional skill.[7]
Definition of “invention” in Patent Act
The statutory basis that MMT are unpatentable lies in section 2 of the Patent Act, which defines:
invention means 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;
The FCA confirmed that that MMT do not meet the definition of “invention” of Patent Act.[8] However, the statutory language does not explicitly between vendible product versus skill and judgment.
The Canadian Generic Pharmaceutical Association argues that Canada has at all material times considered the “professional arts” (and in particular MMT) unpatentable as squarely outside the “invention” definition, eliminating the need for express statutory carve-out. According to CGPA, dosing regimens are merely methods of treating patients and do not constitute an “invention” within the meaning of the Patent Act.
Harmonization vs Domestic Policy
One of the interveners at the hearing is the International Federation of Intellectual Property, which argues that prohibiting claims to dosing regimens in Canada would diverge from the approach taken in comparable jurisdictions such as EU, UK, AU, and US where claims to dosing regimens are considered patentable subject matter.
Canada’s Patent Act differs from that of various European countries, which contain explicit and narrow prohibitions to claiming some forms of MMT. These express prohibitions are required because claims methods of medical treatment are otherwise patentable subject matter in those jurisdictions.
The International Federation of Intellectual Property argues that in the absence of a similar provision in Canada’s Patent Act, claims to MMT are not precluded.
This raises the broader question: should Canada align and follow international harmonization, or prioritize its own public policy considerations?
Possible Guidance from the SCC
The SCC now faces the opportunity to bring long-overdue clarity to the law on MMT. It could take several approaches:
Maintain and Clarify: The SCC may confirm that some form of preclusion for MMT already exists under the Patent Act, but clarify its scope and application.
Expand the exclusion: The SCC could maintain a general exclusion of MMT from patentable subject matter, but articulate a test that reconciles inconsistent case law and is easier to apply.
Reformthe Doctrine: The SCC may find that the prohibition on MMT to be unsound, holding such claims should be treated like any other pharmaceutical innovation, provided they meet the other requirements of the Patent Act.
Defer to Parliament: The SCC could remove the prohibition entirely, leaving it to Parliament to enact a specific statutory exclusion if desired.
This decision has the potential to reshape the landscape for both innovator and generic manufacturers, offering much-needed certainty
[1] Janssen Inc. v. Pharmascience Inc., 2022 FC 1218 at para 164.[2] Pharmascience Inc. v. Janssen Inc., 2024 FCA 23 at para 37.[3] Tennessee Eastman Co. et al. v. Commissioner of Patents, [1974] SCR 111 at 118 [Tennessee].[4] Imperial Chemical Industries Ltd. v. Commissioner of Patents, [1986] 3 FC 40 (F.C.A.) at 50.[5] Pharmascience Inc. v. Janssen Inc., 2024 FCA 23 at para 26.[6] Pharmascience Inc. v. Janssen Inc., 2024 FCA 23 at paras 22-23.[7] Apotex v Welcome, 2002 SCC 77 at para 49; Shell Oil Co. v. Canada, [1982] 2 S.C.R. 536 at 554.[8] Pharmascience Inc. v. Janssen Inc., 2024 FCA 23 at para 19, Tennessee at 118, approved by FCA in Shell Oil and Wellcome.