Patentability And The Supreme Court: Conundrums Surrounding Methods Of Medical Treatment

The Supreme Court is expected to release a much-anticipated patent decision involving pre-filled syringes of paliperidone palmitate used in a dosing regimen to treat schizophrenia.

In advance of this decision, we provide some background on aspects of Canadian patent law that relate to one of the questions before the Supreme Court. Although the Federal Court of Appeal determined that the patent at issue does not claim a method of medical treatment, the Supreme Court is still expected to nevertheless address the broader question of: are methods of medical treatment patentable?

For summaries of the Federal Court of Appeal’s decision in Pharmascience v Janssen and the arguments before the Supreme Court including from the interveners, please find our colleagues’ articles here and here, respectively.

The Patent Act and patentable subject matter generally

Canadian Courts, including the Supreme Court of Canada, have emphasized that patent law is wholly statutory:¹

The law of patents is wholly statutory, and has a surprisingly long history. ... In the interpretation and application of patent statutes judge-made doctrine has over the years done much to clarify the abstract generalities of the statutes and to secure uniformity in their application.

Nevertheless it is salutary to be reminded, from time to time, that the general concepts which are the common currency of patent lawyers are founded on a statutory text, and cannot have any other firm foundation.

The Canadian Patent Act defines what can constitute an invention broadly in both English and French, for the purpose of encouraging and protecting innovation in all areas of technology.

The Patent Act defines an invention as follows:²

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;

invention Toute réalisation, tout procédé, toute machine, fabrication ou composition de matières, ainsi que tout perfectionnement de l’un d’eux, présentant le caractère de la nouveauté et de l’utilité. (invention)

The statutory language is extremely open. The terms “any” and “tout/toute” make clear that the definition of invention has a broad reach and the terms “art,” “realisation” and “composition” have broad and non-specific coverage. Similarly, the scope of “machine,” “process / procédé” and “manufacture / fabrication” are unqualified, and for additional clarity, the definition of invention includes “any improvements / tout perfectionnement” to the foregoing list.

The legislative intention is unambiguous and ambitious: if an inventor has something that is new and useful, subject to other sections of the Patent Act that may restrict what can be claimed (which is currently subsection 27(8)), the inventor should be able to secure a patent for the new and useful invention.

Novelty, utility, and inventiveness are separate validity attacks and should not be comingled with patentable subject matter (nor with one another for that matter). Each validity attack is intended to stand alone and is not meant to be combined into an illegitimate amalgam of validity attacks.³ Thus, the analysis of whether a claimed invention comprises patentable subject matter should be conducted on its own, separately, and apart from whether it is novel, useful, inventive, sufficiently disclosed, etc.⁴ 

Momentary digression from the medical arts to consider other exceptions to patentable subject matter in the Patent Act

Going back historically, not all arts, processes, machines, manufactures or compositions of matter, or their improvements, were considered patentable. For example, the Supreme Court considered the patentability of plant genes and cells (patentable) and a transgenic “oncomouse” (not patentable) in Monsanto and Harvard College, respectively. In drawing a line on patentability, the Court held that higher life forms were outside the scope of an “invention” in s. 2 of the Patent Act and were not properly considered an “art,” “process,” “machine,” “manufacture” or “composition of matter” though the modified cells of which they are comprised were patentable.⁵

As discussed above, while section 2 of the Patent Act is drafted extremely broadly, the Court has nevertheless at times held patents to be invalid on this basis. Exclusions have generally been based upon the nature of the invention claimed and how it fits into the categories of the section 2 definition. But these exceptions are appropriately rare, given the statutory language involved. 

For statutory limitations as to subject matter, the Patent Act only precludes a mere scientific principle or abstract theorem from what may be patented:⁶

27(8) No patent shall be granted for any mere scientific principle or abstract theorem.

27(8) Il ne peut être octroyé de brevet pour de simples principes scientifiques ou conceptions théoriques.

Mathematical formulae

The Court of Appeal has interpreted the statutory exclusion to patentability in subsection 27(8) (formerly 28(3)) in Schlumberger, where a patent claiming a process of converting measurements from boreholes into useful information through a computer program was considered unpatentable.

While argued to be a “process” under section 2, the Court held that the purported invention was rather a mathematical formula that was assimilated to a mere scientific principle or abstract theorem and not patentable merely because the calculations were performed by a computer.⁷

Professional skills

In a 1970 decision, Lawson v Commissioner of Patents, the Exchequer Court concluded that a patent for a “method of describing and laying out parcels of land in a plan of subdivision” was not patentable.⁸ Despite being a method on its face, the Court suggested that an invention must be a “vendible product” and not an art of professional skill.⁹ It likened the patent at issue to a surgeon devising a method of performing an operation, or a lawyer developing a method of cross-examination.¹⁰ The analogies are not altogether apt, but all three examples do represent exercises of professional skill in different circumstances. 

In line with its comment about being a “vendible product”, the Court in Lawson also emphasized that the subject matter of a patent must be economic, citing Dixon C.J. in National Research Development Corporation’s Application (Australia), [1961] RPC 135 at 145. The statement in this decision that methods of surgery were excluded from the concept of invention because they are non-economic relies on another Australian decision from 1938:¹¹

“The point is that a process, to fall within the limits of patentability which the context of the Statute of Monopolies has supplied, must be one that offers some advantage which is material, in the sense that the process belongs to a useful art as distinct from a fine art (see Virginia-Carolina Chemical Corporation’s Application, [1958] R.P.C. 35 at p. 36) — that its value to the country is in the field of economic endeavour. (The exclusion of methods of surgery and other processes for treating the human body may well lie outside the concept of invention because the whole subject is conceived as essentially non-economic: see Maeder v. Busch (1938), 59 C.L.R. 684 at p. 706.)”

Whether a method for treating the human body or other professional skill should be considered non-economic in 2026, as they were in Maeder v. Busch in 1938 and Lawson in 1970, may be worth reconsideration. Certainly, architectural plans and legal courses on cross-examination are considered vendible products or services today. The sentiment that an invention must be economical or commercially useful was repeated in Shell Oil in 1982, when the Court held that a new use for a known compound was properly considered an “art”.¹²

Business methods in computer programs reconsidered

More recently in the Amazon decision, the Federal Court of Appeal applied logic to the question of patentable subject matter in a way that aligns more generally with the language of the Patent Act being interpreted broadly, to allow for patent protection of new and evolving technologies. In Amazon, the Court indicated that business methods can be patentable, despite having been historically prohibited, depending largely on the construction of the claims and whether they may be distinguished from Schlumberger.

In Amazon, the patentee sought to claim its “one-click” method as a (business) method. The Federal Court of Appeal recognized that the limitation on patentable subject matter that had been applied by the Commissioner did not align with the statutory language of the legislation.¹³ The Amazon decision also reflects that times have changed; where computer software was once viewed as a literary text for making rapid calculations, its capabilities by 2011 far exceeded that outdated view of computer programs and deserved patent protection for the investments made in accordance with the Patent Act. In confirming that business methods were not unpatentable subject matter, Canada was also following a trend that had been set by other trading partners.¹⁴ 

The Federal Court of Appeal considered the patentability of a computer-implemented invention again recently in Benjamin Moore, where it indicated the Commissioner should maintain an open mind regarding the patentability of subject matter involving the use of conventional computer technology and not hastily conclude that such subject matter is unpatentable.¹⁵ The Court confirmed that Schlumberger remains at one end of the spectrum in terms of (un)patentable subject matter.¹⁶

Patentable subject matter and methods of medical treatment more particularly

The interplay between patentable subject matter and methods of medical treatment goes further than looking at another method that had historically been prohibited,¹⁷ or an alleged professional skill, in isolation.

The analysis of the patentability of a method of medical treatment in the case law stems from a now-repealed provision of the Patent Act that included a more specific prohibition on claiming methods of medical treatment. In 1970, methods of medical treatment had been precluded from patentable subject matter on the basis of former s. 41(1) of the Patent Act, which was repealed in 1987. This section had read as follows:

41.(1) In the case of inventions relating to substances prepared or produced by chemical processes and intended for food or medicine, the specification shall not include claims for the substance itself, except when prepared or produced by the methods or processes of manufacture particularly described and claimed or by their obvious chemical equivalents.

41. (1) Lorsqu'il s'agit d'inventions portant sur des substances préparées ou produites par des procédés chimiques et destinées A l'alimentation ou à la médication, le mémoire descriptif ne peut comprendre les revendications pour la substance même, sauf lorsque la substance est préparée ou produite par les modes ou procédés de fabrication décrits en détail et revendiqués, ou par leurs équivalents chimiques manifestes.

In Tennessee Eastman, the Supreme Court considered the patentability of the use of a known adhesive for medical purposes. The Court held that given s. 41(1) of the Patent Act, and that the substance at issue was intended for medicine, in order for the substance itself to be eligible for a patent, the claims for the medicine must be limited by the methods or processes of manufacture. More bluntly, a patentee could not circumvent the statutory prescription requiring claims for medicines to be limited to how the medicine was made, to permit others to make and sell the same medicine when made by a non-offending process. This limitation for claiming an invention for a substance intended for medicine only when its method of manufacture was also claimed was repealed in 1987.

Where the substance in Tennessee Eastman was already known, and rather the patent related to a new use of the substance as a surgical (medical) treatment, the Court considered that a method of medical treatment using such a substance could not be patented as it would too easily circumvent the limitation on the patentable subject matter for an invention enunciated in s. 41(1). That reasoning, however, was premised on the existence of the particular legislative scheme in force at that time as embodied in s. 41 of the Patent Act as it then was. 

Given the repeal of s. 41 as it then was and the current absence of any statutory prohibition of this type of patent claim in the Patent Act, there no longer appears to be any statutory basis for precluding claims to methods of medical treatment as unpatentable subject matter that would otherwise be considered a new and useful art, process, machine, manufacture, composition of matter, or improvement thereof. That is not to preclude other attacks on patent validity being properly raised as separate rubrics under the Patent Act for attacking the validity of a patent. But each validity attack must stand upon its own merits and not be comingled to secure a policy objective that is not legislated in the Patent Act.

As Tennessee predated Angiotech by decades, that principle may not have been as clearly recognized as it should now be.

The framework post TRIPS and other trade agreements

The TRIPS negotiations and TRIPS Agreement permitted member countries to exclude “diagnostic, therapeutic and surgical methods for the treatment of humans or animals” from patentable subject matter.¹⁸ Indeed, in article 53(c) of the European Patent Convention, legislators explicitly included methods of medical treatment as an “exception to patentability”:

European patents shall not be granted in respect of:

(…)

(c) methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body; this provision shall not apply to products, in particular substances or compositions, for use in any of these methods.

Canada currently has no such legislation. Absent legislation implementing those policies in Canada, there is no proper basis upon which to find such a prohibition. 

The claims at issue in Canadian patent 2,655,335

In the case currently before the Supreme Court, the innovation for which protection was sought could be broadly categorized as a “use” of a dosage form for treatment (an “art”), a “process” for providing a treatment, and pre-filled syringes (“a machine or a manufacture”) for implementing that use or process, based upon the language of some claims in Canadian patent 2,655,335 (the 335 Patent).

The brief commentary on the claims offered below is intended as a logical summary of key elements for examining the available claim types and whether they can constitute patentable subject matter under the Patent Act, section 2.

Claim 1 is for prefilled syringes comprising a depot formulation of paliperidone palmitate where one syringe provides a loading dose, a second syringe provides a second loading dose to be administered approximately one week after the first loading dose, and another syringe provides the monthly administered maintenance dosing after the second loading dose, all syringes to be used for intramuscular injection in a patient suffering from a disease associated with schizophrenia, schizoaffective or schizophreniform disorders (the “Conditions”). 

Claim 17 claims the use of a dosage form of a depot formulation of paliperidone palmitate by intramuscular injection to treat the Conditions wherein the dosage form comprises a first loading dose, a second loading dose administered approximately one week later and a monthly maintenance dose administered after the second loading dose. 

The language of claim 17 essentially parallels the language of claim 1, but claim 1 is recited as pre-filled syringes which are also “dosage forms”, whereas claim 17 is framed as a “use” claim.

What types of claims are these under Section 2?

A dosage form is a device that is operable (a “machine” or a “manufacture” or a “composition of matter” writ large) holding a medicine (a “composition of matter”) and here contains a depot formulation (another “composition of matter”) of paliperidone palmitate (another “composition of matter”) for use on a certain schedule in a certain manner (a “use” or a “process” for use, similar to Shell Oil) to treat the Conditions.

The Supreme Court’s decision in Shell Oil supports a generous interpretation of the term invention in section 2.¹⁹ As Justice Wilson stated:

What then is the ‘invention’ under s. 2? I believe it is the application of this new knowledge to effect a desired result which has an undisputed commercial value and that it falls within the words ‘any new and useful art’.²⁰

Whether ‘a pre-filled syringe dosing regime for use in a patient suffering a Condition’ or ‘the use of a pre-filled syringe dosing regime to treat a Condition’ is patentable as an “invention” under section 2, as a new and useful art, process, machine, manufacture or composition of matter as the FCA concluded, or whether such claims are considered methods of medical treatment and, if so, whether that provides a basis upon which to find they are unpatentable, are questions with which the Supreme Court must grapple.

However, it would appear that the Patent Act has no current statutory restrictions to constrain patentability. A jurisprudential restriction absent explicit incorporation of such subject matter into the Patent Act in accordance with the TRIPS Agreement, and absent former section 41 of the Patent Act, which was used as a basis for the Court in Tennessee Eastman to determine the use of a known adhesive for surgical purposes was not patentable, would seem to run counter to the legislative intent of the Patent Act.

Conclusions

The outcome of the Pharmascience v Janssen case is expected to provide clarity to the pharmaceutical industry and others involved in the prosecution and enforcement of such patent claims. That clarification will hopefully respect the broad language and the statutory exclusions that have been incorporated (and in some cases removed) from the Patent Act along with the legislative intent of fostering protection for creations covering a broad range of human endeavours. 

Read the original article on GowlingWLG.com

Footnotes

1. Apotex v Sanofi, 2008 SCC 61 at para 12 citing Synthon B.V. v. SmithKline Beecham plc, [2006] 1 All E.R. 685, [2005] UKHL 59, at paras 57-58

2. Patent Act, RSC 1985, c P-4, s. 2

3. Conor Medsystems Incorporated v Angiotech Pharmaceuticals Incorporated, [2008] UKHL 49 per Lord Hoffmann at paragraph 17; see also AstraZeneca v Apotex, 2017 SCC 36 (“AstraZeneca”) at paras 40-44 and the Court’s discussion of how the Promise Doctrine improperly incorporated s. 27(3) into the assessment of a patentable invention under s. 2.

4. To the extent the Court of Appeal in Benjamin Moore at paras 70-72 and 78 suggested that considering novelty and obviousness in the assessment of patentable subject matter or the “invention” has not yet been considered or precluded by Canadian law, the authors view such an approach as inconsistent with AstraZeneca and incorrect at law.

5. Monsanto v Schmeiser, 2004 SCC 34 at paras 21-22; Harvard College v Canada, 2002 SCC 76 at paras 155-166

6. Patent Act, 1985 c P-4, s. 27(8)

7. Schlumberger Canada Ltd. v. Commissioner of Patents, [1982] 1 FC 845 at 847 (FCA); then subsection 28(3)

8.Lawson v Commissioner of Patents, 1970 62 CPR 101 at 117 (CA EXC, Cattanach J.)

9. Lawson v Commissioner of Patents, 1970 62 CPR 101 at 111 (CA EXC)

10. Lawson v Commissioner of Patents, 1970 62 CPR 101 at 110-111 (CA EXC)

11. Lawson v Commissioner of Patents, 1970 62 CPR 101 at 110-111 (CA EXC) quoting Dixon, CJ in National Research Development Corporation's Application (Australia), [1961] RPC 135 at 145.

12. Shell Oil v Commissioner of Patents, 1982 SCR 2 536 at 554-555

13. Amazon at paras 59-60

14. See our colleague’s article discussing Amazon here. 

15. Canada v Benjamin Moore, 2023 FCA 168 at para 85

16. Canada v Benjamin Moore, 2023 FCA 168 at paras 87-88

17. A “process” pursuant to section 2 of the Patent Act encompasses a method of doing something. When considering a “method of medical treatment”, it should be noted that the Supreme Court has previously considered the term “method” to be synonymous with “process”: Tennessee Eastman, [1974] SCR 111 at 117

18. Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS Agreement), Art 27

19. Shell Oil v Commissioner of Patents, 1982 SCR 2 536 at 554

20. Shell Oil v Commissioner of Patents, 1982 SCR 2 536 at 549