Sufficiency

Subsection 27(3) of the Patent Act sets out what is sometimes referred to as the disclosure or sufficiency requirement.

Specification

27 (3) The specification of an invention must

1. correctly and fully describe the invention and its operation or use as contemplated by the inventor;
2. set out clearly the various steps in a process, or the method of constructing, making, compounding or using a machine, manufacture or composition of matter, in such full, clear, concise and exact terms as to enable any person skilled in the art or science to which it pertains, or with which it is most closely connected, to make, construct, compound or use it;
3. in the case of a machine, explain the principle of the machine and the best mode in which the inventor has contemplated the application of that principle; and
4. in the case of a process, explain the necessary sequence, if any, of the various steps, so as to distinguish the invention from other inventions.

Minerals Separation dealt with the requirements of a predecessor to subsections 27(3) and (4) of the Patent Act. The earlier provision read as follows:

14 (1) The specification shall correctly and fully describe the invention and its operation or use as contemplated by the inventor. It shall set forth clearly the various steps in a process, or the method of constructing, making or compounding, a machine, manufacture, or composition of matter. It shall end with a claim or claims stating distinctly the things or combinations which the applicant regards as new and in which he claims an exclusive property and privilege.

In accordance with this provision, President Thorson stated in the passage below that the specification must correctly and fully describe the invention and its operation or use as contemplated by the inventor. He explained that the purpose underlying this requirement is that when the period of monopoly has expired the public will be able, having only the specification, to make the same successful use of the invention as the inventor could.

Two things must be described in the disclosures of a specification, one being the invention, and the other the operation or use of the invention as contemplated by the inventor, and with respect to each the description must be correct and full. The purpose underlying this requirement is that when the period of monopoly has expired the public will be able, having only the specification, to make the same successful use of the invention as the inventor could at the time of his application. The description must be correct; this means that it must be both clear and accurate. It must be free from avoidable obscurity or ambiguity and be as simple and distinct as the difficulty of description permits. It must not contain erroneous or misleading statements calculated to deceive or mislead the persons to whom the specification is addressed and render it difficult for them without trial and experiment to comprehend in what manner the invention is to be performed. It must not, for example, direct the use of alternative methods of putting it into effect if only one is practicable, even if persons skilled in the art would be likely to choose the practicable method. The description of the invention must also be full; this means that its ambit must be defined, for nothing that has not been described may be validly claimed. The description must also give all information that is necessary for successful operation or use of the invention, without leaving such result to the chance of successful experiment, and if warnings are required in order to avert failure such warnings must be given. Moreover, the inventor must act uberrima fide and give all information known to him that will enable the invention to be carried out to its best effect as contemplated by him. This statement of the extent to which the disclosures must go in describing the invention and its operation or use as contemplated by the inventor, if the patent is not to fail for either the ambiguity or insufficiency of such description, is abstracted from a number of cases cited by counsel for defendant: [Citations omitted.]. Section 14. (1) does not, in my opinion, alter the requirements of the law, as laid down in the cases; it merely puts them into statutory form. If they are not complied with, then the patent fails, not for ambiguity or insufficiency of description, as the cases put it, for the Act does not refer to these terms, but for non-compliance with statutory conditions. The result is the same.

When it is said that a specification should be so written that after the period of monopoly has expired the public will be able, with only the specification, to put the invention to the same successful use as the inventor himself could do, it must be remembered that the public means persons skilled in the art to which the invention relates, for a patent specification is addressed to such persons. [pp. 316-318]

Justice Dickson of the Supreme Court of Canada referred to section 36 of the Patent Act (now subsections 27(3) and (4)). He accepted that, as part of the consideration for obtaining a patent, the inventor must give to the public an adequate description of the invention with sufficiently complete and accurate details as will enable a workman, skilled in the art to which the invention relates, to construct or use that invention when the period of the monopoly has expired.

Section 36 of the Patent Act lies at the heart of the whole patent system. The description of the invention therein provided for is the quid pro quo for which the inventor is given a monopoly for a limited term of years on the invention. As Fox points out in Canadian Patent Law and Practice (4th ed.), p. 163, the grant of a patent is in the nature of a bargain between the inventor on the one hand and the Crown, representing the public, on the other hand. The consideration for the grant is twofold: first, there must be a new and useful invention, and secondly, the inventor must, in return for the grant of a patent, give to the public an adequate description of the invention with sufficiently complete and accurate details as will enable a workman, skilled in the art to which the invention relates, to construct or use that invention when the period of the monopoly has expired. The description to which Fox refers is that required by s. 36 of the Patent Act. [p. 517]

Justice LeBel of the Supreme Court of Canada explained the patent bargain and the role of the patent specification. He reiterated that the inventor is granted exclusive rights in an invention in exchange for disclosure of the invention so that society can benefit from this knowledge:

C. The Patent Bargain

[31] The issues in this appeal are best understood by reference to the fundamental principles underlying the patent system. As the courts below noted, sufficiency of disclosure lies at the very heart of this system. If the issues are viewed through this lens, the case becomes more straightforward, and the conclusion flows easily from this principle.

[32] The patent system is based on a bargain, or quid pro quo: the inventor is granted exclusive rights in a new and useful invention for a limited period in exchange for disclosure of the invention so that society can benefit from this knowledge. This is the basic policy rationale underlying the Act. The patent bargain encourages innovation and advances science and technology. Binnie J. explained the quid pro quo as follows in AZT, at para. 37:

A patent, as has been said many times, is not intended as an accolade or civic award for ingenuity. It is a method by which inventive solutions to practical problems are coaxed into the public domain by the promise of a limited monopoly for a limited time. Disclosure is the quid pro quo for valuable proprietary rights to exclusivity which are entirely the statutory creature of the Patent Act.

[33] The role of the patent specification in the quid pro quo was described as follows by Lord Halsbury in Tubes, Ld. v. Perfecta Seamless Steel Tube Company, Ld. (1902), 20 R.P.C. 77, at pp. 95-96:

… if one has to look at first principles and see what the meaning of a Specification is … why is a Specification necessary? It is a bargain between the State and the inventor: the State says, If you will tell what your invention is and if you will publish that invention in such a form and in such a way as to enable the public to get the benefit of it, you shall have a monopoly of that invention for a period of fourteen years. That is the bargain. The meaning which I think, in my view of the Patent Law, has always been placed on the object and purpose of a Specification is that it is to enable, not anybody, but a reasonably well informed artisan dealing with a subject-matter with which he is familiar, to make the thing, so as to make it available for the public at the end of the protected period. [Emphasis added.]

Lord Halsbury’s view was cited with approval by Dickson J. (as he then was) in Consolboard, at p. 523.

[34] Therefore, adequate disclosure in the specification is a precondition for the granting of a patent. As Hughes J. stated in Eli Lilly Canada Inc. v. Apotex Inc., 2008 FC 142, 63 C.P.R. (4th) 406, at para. 74:

Thus, one must both advance the state of the art and disclose that advance in order to gain the patent monopoly. Failing to do so, thus invalidating the monopoly, can be in the form of one or more of several matters such as, the invention was not new, or the so-called invention was obvious or the disclosure was insufficient or what you disclosed doesn’t support the monopoly that you claim.

[35] The issues in this case must be considered in light of the quid pro quo: Is the public getting what it ought to be getting in exchange for exclusive monopoly rights?

As stated by the Supreme Court of Canada in Baldwin:

• the specification should give a full and correct description of the invention and its operation or use;
• if the invention is a process, the specification should set forth clearly the various steps in the process; and
• if the invention is a machine, manufacture, or composition of matter, the specification should explain the method of constructing, making or compounding the same.

Referring to section 14 of the Patent Act (now subsections 27(3) and (4)), Justice Rinfret said:

The section requires that:

The specification shall

1. correctly and fully describe the invention and its operation or use as contemplated by the inventor;
2. set forth clearly the various steps in a process, or the method of constructing, making or compounding, a machine, manufacture, or composition of matter;
3. end with a claim or claims stating distinctly the things or combinations which the applicant regards as new and in which he claims an exclusive property and privilege.

What is required, therefore, under our law, is that the applicant should give a full and correct description of the invention and its operation or use. If the invention is a new process, he should set forth clearly the various steps in the process; if a machine, manufacture, or composition of matter, the specification should explain the method of constructing, making or compounding the same. Then, in every patent, the claim or claims must state distinctly what the applicant regards as new and in which he claims an exclusive property and privilege. … [p. 105]

The patent at issue in this case dealt with an acoustic device, namely a loudspeaker. Justice Rinfret noted that the inventor correctly and fully described the invention and indicated the method of constructing and making the invention.

Here the combination itself is the only thing which Wente regarded as his invention. He correctly and fully described it in the description part of the specification. He indicated the method of constructing and making the new combination in the detailed description and in the accompanying drawing which forms an essential part of the patent; and, upon a fair construction of claims 4 and 9 construed with reference to the entire specification, there can be no doubt, in our view, of the exact nature of the invention which he claimed as new … [p. 106]

A specification is addressed to persons skilled in the art and, therefore, is to be construed by the standard of what such a person would understand on reading it.

The specification in effect fully describes not only the invention, as the learned trial judge found, but also its operation or use. Although, in terms, the various steps are described only for the chloro-ethane process, in fact the same steps are involved when using the bromo-ethane starting material and any person skilled in the art knows that this is what should be expected in the absence of any mention of an anomaly in the behaviour of the bromo-ethane compound. It does not appear to me that a patent should be invalidated on account of such a technicality and I do not think that s. 36(1) so requires. A specification is addressed to persons skilled in the art and, therefore, is to be construed by the standard of what such a person would understand on reading it. The evidence is clear that a competent chemist reading the specification and setting out to prepare thioridazine by the bromo-ethane process would understand that the same steps are to be taken as for the chloro-ethane process.

[pp. 1346-1347]

In Consolboard, the Supreme Court of Canada reviewed the Patent Act’s disclosure requirements. Justice Dickson observed that section 36 of the Patent Act (now subsections 27(3) and (4)) did not lend itself to a tight, literal interpretation.

It cannot be said that s. 36 of the Act is happily phrased. It gives the impression of a mélange of ideas gathered at random rather than an attempt to enunciate, clearly and concisely, a governing principle or principles. This is perhaps understandable in that the section is the product of amendment over a period of many years. The language simply does not lend itself to a tight, literal interpretation. It is, and should be treated as, a parliamentary pronouncement, in general terms, of that which must be set forth by the applicant to the world before being qualified to receive the grant of monopoly under a patent. [p. 518]

He pointed out that, despite changes to the Patent Act, the law laid down by the Supreme Court of Canada in Baldwin was still good law. Justice Dickson concluded that, in essence, what is called for in the specification is a description of the invention and the method of producing or constructing it. Moreover, the description must allow a person skilled in the art, having only the specification, to make the same successful use of the invention as the inventor could. Also, the whole of the disclosure and the claims must be looked at to ascertain the nature of the invention and methods of its performance.

[T]he law laid down by this Court in Baldwin International Radio Company of Canada, Limited v. Western Electric Company Incorporated, and Northern Electric Company, Limited [[1934] SCR 94, [Baldwin]] is still good law, notwithstanding the changes in the Patent Act made in 1935. In Baldwin Rinfret J., as he then was, speaking for the Court, referred to s. 14 of the Patent Act, (now s. 36) and then said:

The section requires that:

The specification shall

1. correctly and fully describe the invention and its operation or use as contemplated by the inventor;
2. set forth clearly the various steps in a process, or the method of constructing, making or compounding, a machine, manufacture, or composition of matter;
3. end with a claim or claims stating distinctly the things or combinations which the applicant regards as new and in which he claims an exclusive property and privilege.

What is required, therefore, under our law, is that the applicant should give a full and correct description of the invention and its operation or use. If the invention is a new process, he should set forth clearly the various steps in the process; if a machine, manufacture, or composition of matter, the specification should explain the method of constructing, making or compounding the same. Then, in every patent, the claim or claims must state distinctly what the applicant regards as new and in which he claims an exclusive property and privilege. If the invention be a new thing, or the improvement of a thing, he must so state; but where the invention consists merely in the new combination of old elements or devices, such combination is sufficiently described if the elements or devices of which it is composed are all named and their mode of operation given and the new and useful result to be accomplished pointed out (Compare: Bates v. Coe, (1878) 98 U.S. 31). It is only if the applicant desires to claim invention for a subordinate element per se that it is necessary for him to claim the element separately, if he wishes to secure in it an exclusive property and privilege. [at p. 105]

In essence, what is called for in the specification (which includes both the disclosure, i.e. the descriptive portion of the patent application, and the claims) is a description of the invention and the method of producing or constructing it, coupled with a claim or claims which state those novel features in which the applicant wants an exclusive right. The specifications must define the precise and exact extent of the exclusive property and privilege claimed.

Section 36(1) seeks an answer to the questions: What is your invention? How does it work? With respect to each question the description must be correct and full in order that, as Thorson P. said in Minerals Separation North American Corporation v. Noranda Mines, Limited [[1947] Ex CR 306]:

… when the period of monopoly has expired the public will be able, having only the specification, to make the same successful use of the invention as the inventor could at the time of his application. [at p. 316]

We must look to the whole of the disclosure and the claims to ascertain the nature of the invention and methods of its performance, (Noranda Mines Limited v. Minerals Separation North American Corporation [[1950] SCR 36]), being neither benevolent nor harsh, but rather seeking a construction which is reasonable and fair to both patentee and public. There is no occasion for being too astute or technical in the matter of objections to either title or specification for, as Duff C.J.C. said, giving the judgment of the Court in Western Electric Company, Incorporated, and Northern Electric Company v. Baldwin International Radio of Canada [[1934] SCR 570], at p. 574, where the language of the specification, upon a reasonable view of it, can be so read as to afford the inventor protection for that which he has actually in good faith invented, the court, as a rule, will endeavour to give effect to that construction. Sir George Jessel spoke to like effect at a much earlier date in Hinks & Son v. Safety Lighting Company [(1876), 4 Ch D 607]. He said the patent should be approached with a judicial anxiety to support a really useful invention.

[Footnotes incorporated; pp. 519-21]

In the instant case, the Federal Court of Appeal had stated that section 36 required the applicant to describe the utility of the invention (in the sense defined by section 2 of the Patent Act). Justice Dickson was of the opinion that the Federal Court of Appeal confused the utility requirement of section 2, with the requirement that the specification disclose the use to which the inventor conceived the invention could be put.

I am […] of the opinion that s. 36(1) does not impose upon a patentee the obligation of establishing the utility of the invention.

…

In my respectful opinion the Federal Court of Appeal erred […] in holding that s. 36(1) requires distinct indication of the real utility of the invention in question.

…

Although (i) s. 36(1) requires the inventor to indicate and distinctly claim the part, improvement or combination which he claims as his invention and (ii) to be patentable an invention must be something new and useful (s. 2), and not known or used by any other person before the applicant invented it (s. 28(1)(a)), I do not read the concluding words of s. 36(1) as obligating the inventor in his disclosure or claims to describe in what respect the invention is new or in what way it is useful. He must say what it is he claims to have invented. He is not obliged to extol the effect or advantage of his discovery, if he describes his invention so as to produce it.

As Thorson P. stated in R. v. American Optical Company et al.[(1950), 11 Fox Pat. C. 62] at p. 85:

Nor is it any objection to the sufficiency of the disclosures that the advantages of the invention as enumerated by Professor Price were not set out in the specification . . . If an inventor has adequately defined his invention he is entitled to its benefit even if he does not fully appreciate or realize the advantages that flow from it or cannot give the scientific reasons for them. It is sufficient if the specification correctly and fully describes the invention and its operation or use as contemplated by the inventor, so that the public, meaning thereby persons skilled in the art, may be able, with only the specification, to use the invention as successfully as the inventor could himself.

With respect, I agree with the submission of counsel for the appellant that the Federal Court of Appeal has confused the requirement of s. 2 of the Patent Act defining an invention as new and useful, with the requirement of s. 36(1) of the Patent Act that the specification disclose the use to which the inventor conceived the invention could be put. The first is a condition precedent to an invention, and the second is a disclosure requirement, independent of the first.

[Footnotes incorporated; p. 521; pp. 525-27]

Justice Lamer said that the inventor must describe not only how the invention can be used but also how a third party can make it.

In summary, the Patent Act requires that the applicant file a specification including disclosure and claims (Consolboard Inc., supra, at p. 520). Canadian courts have stated in a number of cases the test to be applied in determining whether disclosure is complete. The applicant must disclose everything that is essential for the invention to function properly. To be complete, it must meet two conditions: it must describe the invention and define the way it is produced or built (Thorson P. in Minerals Separation North American Corp. v. Noranda Mines Ltd., [1947] Ex. C.R. 306, at p. 316). The applicant must define the nature of the invention and describe how it is put into operation. A failure to meet the first condition would invalidate the application for ambiguity, while a failure to meet the second invalidates it for insufficiency. The description must be such as to enable a person skilled in the art or the field of the invention to produce it using only the instructions contained in the disclosure (Pigeon J. in Burton Parsons Chemicals Inc. v. Hewlett-Packard (Canada) Ltd., [1976] 1 S.C.R. 555, at p. 563; Monsanto Co. v. Commissioner of Patents, [1979] 2 S.C.R. 1108, at p. 1113) and once the monopoly period is over, to use the invention as successfully as the inventor could at the time of his application (Minerals Separation, supra, at p. 316).

…

There is no ambiguity in the wording of s. 36(1): the inventor must describe not only how the invention can be used but also how a third party can make it; nowhere does it say that the deposit by itself of a sample of the invention will meet the disclosure requirement.

[pp. 1637-38; p. 1642]

The Supreme Court of Canada reasserted the general principle that the specification is not required to address why the invention works.

It is generally not necessary for an inventor to provide a theory of why the invention works. Practical readers merely want to know that it does work and how to work it. Normally, it is sufficient if the specification provides a full, clear and exact description of the nature of the invention and the manner in which it can be practised: H. G. Fox, The Canadian Law and Practice Relating to Letters Patent for Inventions (4th ed. 1969), at p. 167. [para. 70]

In Teva, Justice LeBel reaffirmed the reasoning of the Supreme Court of Canada in Consolboard and Pioneer Hi-Bred. He summarized Justice Dickson’s reasoning as the nature of the invention must be disclosed and the entire specification, including the claims, must be considered in determining the nature of the invention and whether disclosure was sufficient.

[49] In Consolboard, this Court reviewed the Act’s disclosure requirements, which at that time were found in s. 36. Although there are variations in wording between that section and the current s. 27(3), the substance of the disclosure requirements has remained the same.

[50] Dickson J. discussed what the specification must contain in order to meet the disclosure requirements. He stated clearly that the nature of the invention must be disclosed and that the entire specification, including the claims, must be considered in determining the nature of the invention and whether disclosure was sufficient … .

…

[52] In Consolboard and in Pioneer Hi-Bred, the Court correctly analysed the disclosure requirements set out in s. 27(3) of the Act. The reasoning in those cases should be reaffirmed and applied in the case at bar.

Justice LeBel clarified that the questions What is your invention? and How does it work? are not the only relevant ones. As stated in Consolboard and Pioneer Hi-Bred, the description must be such as to enable a person skilled in the art of the invention to produce it using only the instructions contained in the specification.

[70] As I noted above, this Court made it clear in Consolboard that the specification, which includes the claims and the disclosure, must define the precise and exact extent of the privilege being claimed so as to ensure that the public can, having only the specification, make the same use of the invention as the inventor (p. 520). In my view, the courts below misread Consolboard when they stated that the only questions that must be answered are What is your invention? and How does it work? Dickson J. did not state that those were the only relevant questions. In fact, quoting Minerals Separation, he went on to say, at p. 520:

With respect to each question the description must be correct and full in order that, …:

… when the period of monopoly has expired the public will be able, having only the specification, to make the same successful use of the invention as the inventor could at the time of his application. [Emphasis added.]

[71] The Court reiterated this in Pioneer Hi-Bred: The description must be such as to enable a person skilled in the art or the field of the invention to produce it using only the instructions contained in the disclosure (p. 1638).

The Federal Court of Appeal summarized the disclosure requirement as follows:

[64] Disclosure lies at the heart of the patent system. The enabling description of an invention in the specification of a patent is the quid pro quo for the monopoly under the Patent Act: Consolboard Inc. v. MacMillan Bloedel (Sask.) Ltd, [1981] 1 S.C.R. 504 at page 517, 122 D.L.R. (3d) 203. Paragraphs 27(3)(a) and (b) set out the requirements that an inventor describe and enable the invention:

27. (3) The specification of an invention must

(a) correctly and fully describe the invention and its operation or use as contemplated by the inventor;

(b) set out clearly the various steps in a process, or the method of constructing, making, compounding or using a machine, manufacture or composition of matter, in such full, clear, concise and exact terms as to enable any person skilled in the art or science to which it pertains, or with which it is most closely connected, to make, construct, compound or use it; …

[emphasis added]

[65] Basically, paragraphs 27(3)(a) and (b) require the inventor to answer two questions: What is your invention? How does it work, in the sense of how to put it into operation? See Consolboard, above at page 520. The purpose of these paragraphs is to ensure that when the monopoly ends, the skilled reader, armed only with the specification, can put the invention into practice: Consolboard at pages 520-21, citing Minerals Separation North American Corporation v. Noranda Mines, Limited, [1947] Ex. C.R. 306 at page 316, 12 C.P.R. 99.

[66] In Pioneer Hi-Bred, the Supreme Court put the test as follows:

The applicant must define the nature of the invention [What is your invention?] and describe how it is put into operation [How does it work?]. A failure to meet the first condition would invalidate the application for ambiguity, while a failure to meet the second invalidates for insufficiency. The description must be such as to enable a person skilled in the art of the field of the invention to produce it using only the instructions contained in the disclosure… and once the monopoly period is over, to use the invention as successfully as the inventor could at the time of his application. [comments added]

(Pioneer Hi-Bred Ltd. v. Canada (Commissioner of Patents), [1989] 1 S.C.R. 1623 at page 1638, 25 C.P.R. (3d) 257.)

[67] The question whether the patent specification sets out in sufficiently clear and exact terms how the invention may be deployed is one of fact: Apotex Inc. v. Lundbeck Canada Inc., 2010 FCA 320, 88 C.P.R. (4th) 325 at paragraph 116. The disclosure must be sufficient as of the date of filing: Teva Canada Ltd. v. Pfizer Canada Inc., 2012 SCC 60, [2012] 3 S.C.R. 625 at paragraph 90.

[68] An inventor need not disclose all modes of the invention. Paragraphs 27(3)(a) and (b) are satisfied if the inventor sufficiently discloses one mode: Abbvie Corporation v. Janssen Inc., 2014 FC 55, 116 C.P.R. (4th) 399 at paragraph 166, rev’d on other grounds 2014 FCA 242; Patent Rules, S.O.R./96-423, paragraph 80(1)(f). Were it otherwise, the requirement that an inventor of a mechanical invention must disclose only the best mode contemplated, as specified by paragraph 27(3)(c) of the Patent Act, would be purposeless.

[French text omitted.]

Justice LeBel stated that the first step in assessing sufficiency is to define the nature of the invention.

The issue was whether each claim in a patent application concerns a separate invention. Lower courts had accepted the broad proposition that, in every case, each claim in a patent application concerns a separate invention.

Justice LeBel rejected this broad conclusion. A patent must contain only one invention. Therefore, in general, each claim is not to be construed as a separate invention. However, a patent will not be found invalid based solely on the reason that it has more than one invention, and it follows that some patents may contain more than one invention, with different claims covering separate inventions. Where this issue is raised, the individual patent is considered on a case-by-case basis. A useful approach is to examine the specification as a whole to determine whether the claims relate to a single general inventive concept.

F. Nature of the Invention

[53] In determining whether the disclosure requirements have been met in this case, the first step is to define the nature of the invention in Patent ’446. This must be done in order to comply with s. 27(3) of the Act, which requires, among other things, that the specification correctly and fully describe the invention. Therefore, we must ask: What is the invention in Patent ’446?

[54] The Federal Court and the Federal Court of Appeal held, based on Boehringer and Apotex ACE (F.C.A.), that each claim in Patent ’446 is a separate invention. As a result, they considered the disclosure requirements with respect to each individual claim.

…

[57] … However, the Exchequer Court’s decision in Boehringer has been misinterpreted. It does not stand for the proposition that every claim in a patent application is a separate invention. Rather, as Teva points out (A.F., at paras. 106-9), the court in Boehringer reached the conclusion that each claim in the patent in question concerned a separate invention only after considering the specification as a whole. The court did not purport to establish a broad proposition that in every case, each claim in a patent application concerns a separate invention. Such a proposition would be contrary to the scheme of the Act.

…

[60] The provisions of s. 36 support the conclusion that each claim should not be construed as a separate invention in every case.

…

[63] In Apotex ACE, the Federal Court of Appeal varied the Federal Court’s decision in part, but upheld the conclusion that separate claims disclose separate inventions. However, as I have stated, this broad conclusion is contrary to the provisions of the Act and must be rejected.

[64] It is possible, as in Boehringer, for each claim in a patent to disclose a separate invention. Where this issue is raised, however, individual patents must be considered on a case-by-case basis. In my view, the approach Teva advocates for at para. 119 of its factum is useful in this case: … the specification as a whole must be examined to determine whether sildenafil and the other compounds claimed in the patent are linked so as to form a single general inventive concept. This is consistent with this Court’s comment in Consolboard, at p. 520: We must look to the whole of the disclosure and the claims to ascertain the nature of the invention and methods of its performance … .

Turning to the facts, and considering the specification as a whole, the Court found that the patent in question had only one inventive concept. In particular, the Court observed that while the singular word invention appeared in the patent, the plural word inventions did not.

[66] In this case, if we consider the specification as a whole, there is nothing to support the view that the use of sildenafil for the treatment of ED is a separate invention from the use of any of the other claimed compounds for that same purpose. No specific attributes or characteristics are ascribed to sildenafil that would set it apart from the other compounds. Even if we take into consideration the fact that sildenafil is an especially preferred compound, there is still nothing that distinguishes it from the other eight especially preferred compounds. The use of sildenafil and the other compounds for the treatment of ED comprises one inventive concept.

[67] In fact, the patent itself suggests that the entire class of claimed compounds will be effective in treating ED. The first sentence of the specification states: This invention relates to the use of a series of [compounds] for the treatment of impotence (A.R., vol. X, at p. 164 (emphasis added)). The following appears on the second page of the specification: Unexpectedly, it has now been found that these disclosed compounds are useful in the treatment of erectile dysfunction. And page 11 of the specification contains this statement:

Thus the invention includes a pharmaceutical composition for the curative or prophylactic treatment of erectile dysfunction in a male animal, including man, comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, together with a pharmaceutically acceptable diluent or carrier. [Emphasis added; A.R., vol. X, at p. 174.]

The plural word inventions does not appear in Patent ’446.

[68] There is no evidence on the record to suggest that Pfizer filed a divisional application under s. 36(2.1). It would be disingenuous for Pfizer to imply that there is one invention in the patent application for the purpose of complying with s. 36(1) and then to submit that each claim concerns a distinct invention for the purposes of this appeal. If Patent ’446 is viewed as a whole, there is only one invention: the use of the compound or compounds that are effective in treating ED.

The specification must fully disclose the invention. It follows that a person skilled in the art must be able to determine the invention having only the specification. If a person skilled in the art is required to conduct tests to determine the invention, then the specification does not fully disclose the invention.

In Viagra, the invention was the use of the compound sildenafil for the treatment of ED. The specification claimed a ranged of compounds and narrowed the effective compound down to two possible compounds — the one found in Claim 6 or the one in Claim 7. Only one of the two compounds actually worked, but the specification did not disclose which one did. The inventor knew that the effective compound was sildenafil, but chose not to disclose that in the specification. A skilled reader having only the specification would not have been able to make the same successful use of the invention as the inventor could at the time of his application because further testing would have been required to pick the right compound.

[70] As I noted above, this Court made it clear in Consolboard that the specification, which includes the claims and the disclosure, must define the precise and exact extent of the privilege being claimed so as to ensure that the public can, having only the specification, make the same use of the invention as the inventor (p. 520).

…

[72] Recall that in this case Pfizer had conducted tests that demonstrated that sildenafil was effective in treating ED. None of the other compounds in Patent ’446 had been shown to be effective in doing so. Therefore, the invention was the use of sildenafil for the treatment of ED. This had to be disclosed in order to meet the requirements set out in s. 27(3) of the Act.

…

[74] The disclosure in the specification would not have enabled the public to make the same successful use of the invention as the inventor could at the time of his application, because even if a skilled reader could have narrowed the effective compound down to the ones in Claim 6 and Claim 7, further testing would have been required to determine which of those two compounds was actually effective in treating ED. As the trial judge stated, at para. 146, [a] skilled reader would then conduct tests on those two compounds and determine which of those compounds worked. And as he also stated, at para. 135, the skilled reader must undertake a minor research project to determine which claim is the true invention.

[75] Pfizer argued in the Court of Appeal that Teva had already been able to make the same use of the invention having only the specification, because it had filed a submission with the Minister of Health for a drug product containing sildenafil (F.C.A., at para. 48). However, this does not change the fact that the specification required, at a minimum, a minor research project in order to determine whether Claim 6 or Claim 7 contained the correct compound. The fact that Teva carried out this minor research project is irrelevant to Pfizer’s obligation to fully disclose the invention. More importantly, what must be considered is whether a skilled reader having only the specification would have been able to put the invention into practice. The trial judge clearly found that the skilled reader would have had to undertake a minor research project to determine what the true invention was.

The Federal Court reiterated the principle from Sanofi that the specification must disclose the invention without the need for any testing or guesswork.

[235] The specification need not set out every minor piece of instruction on how to work the invention. Sufficiency is met even if the skilled reader, once taught the invention by the patent, must still conduct routine experiments to arrive at the desired result (see e.g. Airseal Controls Inc v M & I Heat Transfer Products Ltd (1993), 53 CPR (3d) 259 at 274, 72 FTR 196). However, the specification must disclose the invention itself without the need for any testing or guesswork. If it narrows down the invention to two possible candidates, but fails to teach which one actually works, the patent is insufficient, even if only a minor research project would enable the skilled person to pick the right candidate (Sildenafil at para 74).

The House of Lords in Synthon noted that test of enablement for the purpose of anticipation was the same as that for the purpose of sufficiency. There may however be differences in the application of this test to the facts.

27. […] In the present case the Court of Appeal was reluctant to say that the test of enablement of a prior disclosure for the purpose of anticipation was the same as the test of enablement of the patent itself for the purpose of sufficiency. But I can think of no reason why there should be any difference and the Technical Board of Appeal has more than once held that the tests are the same: see ICI/Pyridine Herbicides [1986] 5 EPOR 232, para 2; COLLABORATIVE/Preprorennin [1990] EPOR 361, para 15. In my opinion, therefore, the authorities on section 72(1)(c) are equally applicable to enablement for the purposes of sections 2(2) and (3). There may however be differences in the application of this test to the facts; for example, because in the case of sufficiency the skilled person is attempting to perform a claimed invention and has that goal in mind, whereas in the case of prior art the subject-matter may have disclosed the invention but not identified it as such. But no such question arises in this case, in which the application plainly identified crystalline PMS as an embodiment of the invention.

In Sanofi, the Supreme Court of Canada left open the question of whether enablement for purposes of sufficiency is identical to enablement for purposes of anticipation in Canada.

[26] If the disclosure requirement is satisfied, the second requirement to prove anticipation is enablement which means that the person skilled in the art would have been able to perform the invention (para. 26). Lord Hoffmann held that the test for enablement for purposes of anticipation was the same as the test for sufficiency under the relevant United Kingdom legislation. (Enablement for the purposes of sufficiency of the patent specification under the Canadian Patent Act, s. 34(1)(b) of the pre-October 1, 1989 Act, now s. 27(3)(b), is not an issue to be decided in this case and my analysis of enablement is solely related to the test for anticipation. The question of whether enablement for purposes of sufficiency is identical in Canada is better left to another day.)

Drawing from UK jurisprudence, the Court arrived at a list of factors that should normally be considered when assessing enablement for purposes of anticipation.

[37] Drawing from this jurisprudence, I am of the opinion that the following factors should normally be considered. The list is not exhaustive. The factors will apply in accordance with the evidence in each case.

1. Enablement is to be assessed having regard to the prior patent as a whole including the specification and the claims. There is no reason to limit what the skilled person may consider in the prior patent in order to discover how to perform or make the invention of the subsequent patent. The entire prior patent constitutes prior art.
2. The skilled person may use his or her common general knowledge to supplement information contained in the prior patent. Common general knowledge means knowledge generally known by persons skilled in the relevant art at the relevant time.
3. The prior patent must provide enough information to allow the subsequently claimed invention to be performed without undue burden. When considering whether there is undue burden, the nature of the invention must be taken into account. For example, if the invention takes place in a field of technology in which trials and experiments are generally carried out, the threshold for undue burden will tend to be higher than in circumstances in which less effort is normal. If inventive steps are required, the prior art will not be considered as enabling. However, routine trials are acceptable and would not be considered undue burden. But experiments or trials and errors are not to be prolonged even in fields of technology in which trials and experiments are generally carried out. No time limits on exercises of energy can be laid down; however, prolonged or arduous trial and error would not be considered routine.
4. Obvious errors or omissions in the prior patent will not prevent enablement if reasonable skill and knowledge in the art could readily correct the error or find what was omitted.

The specification does not need to include steps that are obvious and common knowledge to a person skilled in the art. But it cannot contain something that necessitates the working out of a problem. The disclosure is insufficient if the specification necessitates the working out of a problem.

Finally, I am unable to share appellant’s argument when it says that the fact the invention was discovered partly by chance does not necessarily mean that someone else could not retrace the path that he described in the specification. It is nonetheless clear that apart from steps which appear to be obvious and common knowledge for an experimenter skilled in the art, a person to whom the disclosure is addressed is not required to exercise or to be possessed of more, and, if the specification contains something that necessitates the working out of a problem, the patent cannot be supported (see Fox, op. cit., at p. 171). It is apparent in the case at bar that the steps required for selective reproduction present no problem. However, an experimenter could only discover the steps involved in crossing by empirical means. Without hypothesizing as to why appellant did not comply with the disclosure requirement, I have to say that either Hi-Bred was negligent in failing to describe its procedure correctly or it did indeed make the discovery by chance.

[p. 1641]

The Federal Court of Appeal concluded that there is no reason to exclude some non-inventive trial and error from being used by a skilled person to make the claimed invention. In a field where trial and error experiments are generally carried out, such limited testing is permitted and does not involve an undue burden.

[55] This brings me to the comment of the Federal Court to which Teva also objects. At paragraph 191 of the Reasons, the Federal Court stated that a skilled person would be able to make the claimed formulation based on his or her own knowledge, possibly through some noninventive trial and error (which is permitted per Valence Technology Inc v Phostech Lithium Inc, 2011 FC 174 at para 224), without having to be explicitly told that the calcipotriol must be dissolved in the solvent C.

[56] In adding the last portion of this sentence, the Federal Court appears to be dealing with Teva’s theory that calcipotriol is somewhat special. First, this is only viewed as a possibility, not a probability, and second, the Federal Court simply followed in this respect a decision (Valence) which has been confirmed by our Court in Phostech Lithium Inc. v. Valence Technology Inc., 2011 FCA 237, 422 N.R. 162 [Valence, FCA]. I moreover note that this comment is in line with the law in the U.K. and in Europe (see Synthon BV v. Smithkline Beecham plc, [2005] UKHL 59 at paras. 27, 30). It is also how the Supreme Court of Canada defined an enabling description or disclosure in Apotex Inc. v. Sanofi-Synthelabo Canada Inc., 2008 SCC 61 at para. 43, [2008] 3 S.C.R. 265 [Sanofi-Synthelabo], albeit in a different context (anticipation). The wording of subsection 27(3) of the Act is essentially the same as the provisions applicable in England and in Europe. There is no reason to exclude the limited type of testing that is usually referred to when one uses the expression used by the Federal Court. As Justice Rothstein noted in Sanofi-Synthelabo, in a field such as the one involved before us where trial and error experiments are generally carried out, such limited testing is permitted, and does not involve an undue burden.

…

[59] Furthermore, the Supreme Court refers to the factual findings of the Federal Court in Sildenafil which found that in that case, one would require a minor research project to determine the true invention. This statement of Justice Lebel is, as mentioned, perfectly in line with the law as I understand it, not only in Canada but elsewhere, such as the U.K. and Europe, which recognizes that some non-inventive trial and error may be required to put a properly disclosed invention into practice. Had the Supreme Court wished to change the law on this point in Sildenafil, one would have expected a much more fulsome analysis of the issue and discussion of the relevant authorities. In the absence of such a discussion, I do not believe that the Supreme Court changed the law in Sildenafil in the manner Teva argues.

[60] In any event, what the Federal Court was referring to in the present case was in no way a minor research project within the meaning of Sildenafil. Rather, I would compare it to the trial and error required to determine the most effective way to make a good pancake mix with no lumps, i.e., whether one should put the eggs before or after the flour and sugar are dissolved in milk. The possible need for this sort of trial and error to enable the skilled person to use the invention does not render the disclosure in a patent insufficient.

The Federal Court of Appeal reaffirmed that the fact that some non-inventive trial and error experiments may be required to practice a properly disclosed invention will not per se invalidate a patent on the basis that it fails to meet the requirements of subsection 27(3) of the Act. The Court added that even short experiments will be objectionable if they involve an inventive step, since the nature of the efforts required is also important.

[78] Enablement (how to practice the invention) is a concept completely distinct from the disclosure of the invention itself, the latter of which was at issue in Pfizer. In Leo Pharma, our Court held that the teachings of the Supreme Court of Canada in Pfizer did not change the law as it had been applied to enablement (as opposed to the disclosure of the invention) not only in Canada, but also in the UK (Synthon at paragraph 27 being an example) and continental Europe. The fact that some non-inventive trial and error experiments may be required to practice a properly disclosed invention will not per se invalidate a patent on the basis that it fails to meet the requirements of subsection 27(3) of the Act (see Leo Pharma at paras. 55-59). Unfortunately, this decision was issued a few months after the decision of the Federal Court in the present matter. Thus, it was incorrect for the Federal Court to say that the strict test applicable to the description of the invention applied to the question of whether the disclosure was sufficient to teach the POSITA how to practice the invention. A disclosure will still be enabling if it does not require undue efforts.

[79] However, the Federal Court also took into account the less stringent approach described by Prof. Vaver (David Vaver, Intellectual Property Law, 2^nd Ed., Toronto: Irwin Law, 2011 at p. 342). At paragraph 550 of its reasons, the Federal Court underlines the following sentence from the author: If a person skilled in the art can arrive at the same results only through chance or further long experiments, the disclosure is insufficient and the patent is void.

[80] This statement is more in line with the view expressed in Leo Pharma. It would have been more complete to add that even short experiments will be objectionable if they involve an inventive step, since the nature of the efforts required is also important. The acceptable extent of the efforts that may be required from the POSITA will depend on the nature of the invention and the field to which it pertains.

In the instance case, the effort required to practice the invention would result in a major research project and therefore the disclosure was insufficient to enable the skilled person to practice the invention.

[95] I am satisfied that the factual conclusions reached by the Federal Court were open to it on the evidentiary record. I have not been persuaded that the Federal Court made a palpable and overriding error in concluding that, to practice the invention claimed in each of the RFP Patents, the POSITA would have to undertake a major research project (i.e. undue efforts) because of the lack of sufficient instructions in the disclosures of the RFP Patents.

Where there is a failure to properly disclose the invention and how it works, the patent in question is deemed invalid.

[84] Although s. 27 does not specify a remedy for insufficient disclosure, the logical consequence of a failure to properly disclose the invention and how it works would be to deem the patent in question invalid. This flows from the quid pro quo principle underpinning the Act. If there is no quid — proper disclosure — then there can be no quo — exclusive monopoly rights.

Justice Snider of the Federal Court explicitly considered and rejected the proposition that there is a best mode requirement for inventions other than machines.

[329] As can be seen from the words of the statute, the best mode obligation only arises in the case of a patent to a machine. Neither the words nor the underlying concept that a patentee must set out the best available manner of putting the invention into practice are used elsewhere in s. 34(1) or in the Patent Act. In Sanofi-Synthelabo, above, the Supreme Court reiterated the importance of the statutory scheme when interpreting patents. …

[330] Where Parliament has chosen to include a best mode obligation in respect of machine patents only, the courts must respect that choice. Accordingly, reading such a requirement into non-machine patents would be contrary to the principles of statutory interpretation.

[331] Even if the notion of best mode is applicable, the jurisprudence raises another difficulty. As noted, the Schering scientists developed the new method of synthesis in the time period between the US filing and the Canadian filing. Such a situation was addressed by the Federal Court of Appeal in the case of Lido Industrial Products Ltd. v. Teledyne Industries Inc. (1981), 57 C.P.R. (2d) 29. In that case, involving a patent for a showerhead, the inventors failed to refer to certain improvements to the device that were known to them after the US filing date of September 4, 1973 but before the Canadian filing date of February 27, 1974. In explaining the applicable date for application of the best mode test, Chief Justice Thurlow, speaking for the entire court on this point, concluded that the relevant date was that of the US filing. On that basis, he found (at paragraph 50) that:

While the device with these modifications was contemplated by the applicant Teledyne Industries, Inc. at the material time it has not been established that it was known or contemplated by the applicant as the best mode for the application of the principle of its device.

Thus, on the facts before me, the best mode obligation, even if it applies, would not have required Schering to disclose the better synthesis method in its specification.

[332] I also note that the words of President Thorson in Mineral Separation, above, must be placed in context. President Thorson’s words were obiter only; nowhere in the decision, did President Thorson apply the concept of best mode or good faith to his decision. Further, Justice Dickson’s words referred to above, in the Consolboard decision, were addressed to the issue of sufficiency. In brief, I do not read either of these cases as importing a best mode requirement into a patent for a compound.

The Federal Court of Appeal affirmed the reasoning of Justice Snider. Justice Nadon wrote that there is no best mode requirement unless the invention is a machine.

[43] … Pfizer argues that the Act does not impose a best mode requirement except with respect to machines, nor does it not impose a requirement to distinguish inventions, except for processes. It notes that in Sanofi Aventis Canada Inc. v. Apotex Inc., 2009 FC 676, [2009] 77 C.P.R. (4th) 99 [Sanofi], Snider J. of the Federal Court explicitly considered and rejected the proposition that Minerals Separation (Ex. Ct.), supra, imposes a best mode requirement on inventions other than machines.

…

[72] The appellant’s contention that best mode requirements apply is without merit. In Sanofi, supra, Snider J. carefully examined the Act and concluded, in my view correctly, as follows:

[329] As can be seen from the words of the statute, the best mode obligation only arises in the case of a patent to a machine. Neither the words nor the underlying concept that a patentee must set out the best available manner of putting the invention into practice are used elsewhere in s. 34(1) or in the Patent Act.

[330] Where Parliament has chosen to include a best mode obligation in respect of machine patents only, the courts must respect that choice. Accordingly, reading such a requirement into non-machine patents would be contrary to the principles of statutory interpretation.

[…]

[332] I also note that the words of President Thorson in Mineral Separation, above, must be placed in context. President Thorson’s words were obiter only; nowhere in the decision, did President Thorson apply the concept of best mode or good faith to his decision. Further, Justice Dickson’s words referred to above, in the Consolboard decision, were addressed to the issue of sufficiency. In brief, I do not read either of these cases as importing a best mode requirement into a patent for a compound.

This research paper reviewed the history of the best-mode requirement and suggested that paragraph 27(3)(a) of the Patent Act imposes a best mode duty for all inventions and that the best-mode-for-machines duty in paragraph 27(3)(c) of the Patent Act does not exclude a best mode duty for all other inventions.

Justice Snider reiterated that there is no requirement in section 27(3) that the best mode must be disclosed in inventions that are not machines.

[376] … Section 27(3)(c) of the Patent Act requires that an inventor must in the case of a machine, explain the principle of the machine and the best mode in which the inventor has contemplated the application of that principle (emphasis added). There is no requirement in s. 27(3) that best mode must be disclosed in inventions that are not machines. …

Justice O’Keefe of the Federal Court reiterated that the best mode requirement only applies to inventions relating to machines.

[279] NOVA also stated in its oral argument that the ’705 Patent was insufficient because it failed to disclose the best mode. This argument must fail as there is no requirement to disclose a best mode for the subject matter of the ’705 Patent. The best mode requirement only applies to inventions relating to machines (see Sanofi-Aventis Canada Inc v Apotex Inc, 2009 FC 676 at paragraphs 329 and 330, 350 FTR 156, aff’d on other grounds, 2011 FCA 300). …

[280] NOVA cites the decision in Pfizer Canada Inc v Teva Limited, 2012 SCC 60, [2012] 3 SCR 625, in support of its best mode argument. Even if there was a requirement to disclose the best mode for the ’705 Patent, Teva does not assist the defendant. In Teva, Pfizer failed to disclose the only composition out of many that would work.

Justice O’Reilly of the Federal Court reiterated that the best mode requirement relates solely to machines. He added that a method and a system are not machines.

[146] Finally, Western argues that the inventor had a duty to describe the best mode of putting the invention into practice, citing s 27(3)(c) of the Patent Act, RSC 1985, c. P-4. However, that provision relates solely to machines and, as I understand the patent, it claims a method and a system, not a machine.

Justice Locke opined that it is difficult to understand how claims to a system are not to a machine. He also noted that there is considerable doubt as to whether the best-mode requirement is limited to machines.

[118] The Federal Court dismissed the appellants’ best-mode argument by saying that paragraph 27(3)(c) relates solely to machines and, as I understand the patent, it claims a method and a system, not a machine (see paragraph 146 of the Decision).

[119] I must say that it is difficult to understand how the claims to a system in the 173 Patent are not to a machine. I note that even the Federal Court referred to the patented shale shaker system as a machine at paragraphs 6 and 15 of the Decision. It is not clear to me that defining an invention as a system rather than a machine should eliminate the need to comply with paragraph 27(3)(c) of the Patent Act. In addition, there is considerable doubt as to whether, despite the wording of paragraph 27(3)(c), the best-mode requirement is limited to machines: Donald MacOdrum, Fox on the Canadian Law of Patents, 5th ed. (Carswell) at 7.8(d)(iv); Robert Barrigar & Andrew Shaughnessy, Canadian Patent Act Annotated, 2nd ed. (Carswell) at 27:1570ff; David Vaver, Best Mode Disclosure in Canadian Patents (2013) 25 I.P.J. 303.