In the much-anticipated Supreme Court decision in AstraZeneca Canada Inc. v. Apotex Inc., 2017 SCC 36, the SCC has declared that the so-called “Promise Doctrine” is not the correct approach to determine a patent’s utility under s. 2 of the Patent Act.
Their condemnation of the Promise Doctrine is unequivocal, holding that the Doctrine is not good law, and also pointing out ways in which it was inconsistent with the legislative scheme and prior SCC jurisprudence.
The Promise Doctrine has been applied by the federal courts when making determinations of utility. The Doctrine holds that “where the specification sets out an explicit ‘promise,’ utility will be measured against that promise” (Eli Lilly Canada Inc. v. Novopharm Ltd., 2010 FCA 197,  1 F.C.R. 349, at para. 76). If a patent application promises a specific utility, but that utility cannot be demonstrated or soundly predicted as of the filing date, then the entire patent will be found invalid.
Under the Doctrine, however, when the applicant fulfils the requirements of s. 27(3) of the Patent Act by disclosing any use, such use statements are automatically imported into the analysis of utility under s. 2 of the Patent Act. There is no requirement that the specification include a promise of utility, and without such a promise, a patent would be found to have utility if only a mere scintilla of utility is present in the claims.
The effect of the Doctrine on patent drafting was to encourage patent practitioners in Canada to remove any phrase that might be considered a “promise” by the courts.
Further, if multiple uses were described in the specification, the courts required all of the uses to be sufficiently demonstrated or soundly predicted by the filing date in order for the patent to be valid.
The challenged patent was for AstraZeneca’s highly successful drug esomeprazole, a proton pump inhibitor for reduction of gastric acid, reflux esophagitis and related maladies. Apotex sold its generic version, for which AstraZeneca brought an infringement action, and Apotex counter-claimed to have the patent declared invalid.
The Federal Court had declared that the patent was invalid because of the Promise Doctrine, stating that of the two “promises” made in the patent ((1) the use of esomeprazole to reduce acid in the stomach and (2) to work more effectively for a wider range of people with less variation in patient response), only the use for acid reduction was soundly predicted at the filing date. Therefore, the Court declared the entire patent invalid for lack of utility. The decision was upheld by the Federal Court of Appeal.
In allowing the appeal and ultimately finding the patent valid, the unanimous SCC held that the Promise Doctrine conflated sections 2 and 27(3) (which the SCC had already clarified in the Consolboard decision), importing a requirement that was not supported by the legislative scheme and introducing the potential for unfair consequences. The Doctrine was contrary to the Act in that to invalidate a patent solely on the basis of an unintentional overstatement of even a single use discourages an applicant from fully disclosing the invention, thus running counter to the “bargain theory” at the heart of the patent system.
In addition, the Doctrine was held to be unsupported in that it ran counter to the language in the Act by requiring the demonstration or sound prediction of every stated use. An otherwise useful invention would be denied protection merely because one of multiple stated uses was not established. The Court stated that this was punitive and antagonistic to the aims of the Act.
Furthermore, the Promise Doctrine is inconsistent with the established law on analysis of other issues of validity, such as novelty or non-obviousness, where the claims are given a construction prior to any recourse to the rest of the disclosure. The Promise Doctrine had instead invited the courts to read both the claims and the disclosure to identify potential promises.
Having rejected the Doctrine as bad law, the SCC then presented a two-part analysis to determine the utility of an invention:
- the courts must identify the subject-matter of the invention as claimed in the patent, and
- the courts must ask whether that subject-matter is useful – is it capable of a practical purpose (i.e. an actual result)?
Based on this two-part analysis, utility is now determined solely based on the claims of the patent.
The utility will differ from patent to patent based on the subject matter of the invention as identified by claims construction (not just any use). The claims must be capable of an actual relevant use and not be devoid of utility. Even if the proposed invention has a use unrelated to the subject matter, the unrelated use will not save the claim from being invalid due to lack of utility.
That being said, each claim only requires a scintilla of related utility to meet the threshold as determined by the Act. A single use related to the nature of the subject matter is sufficient, and the utility must be established by either demonstration or sound prediction as of the filing date (Apotex Inc. v. Wellcome Foundation Ltd., 2002 SCC 77 at para. 56).
By setting the utility requirement at the filing date, premature granting of patents is reduced and ensures patents are not granted for speculative inventions.
Nevertheless, even though utility of the subject matter is a requirement of patent validity, an applicant is not required to disclose the utility of the invention to fulfil the requirements of s. 2. Applicants should still be wary of promises within the specification of their patent applications. In Canada, claims are given a purposive construction where the courts look to the specification if ambiguity exists in the claim terms. Any promises in the application may still impact a proper construction. Moreover, promises may affect prosecution and enforcement in other jurisdictions.
While the decision will be welcomed by patent applicants and practitioners alike, there is still potential uncertainty around the issue of identifying uses that are “relevant” to the subject matter of the invention. The Court provides a perhaps tongue-in-cheek example of a machine patent not being saved where the failed machine could be useful as a paperweight, but there may be instances where it might be difficult to determine whether a particular use is in fact relevant to the subject matter of the invention. Questions remain, but the ill-founded Promise Doctrine is no more.