AstraZeneca Canada Inc. v. Apotex Inc., 2017 SCC 36
The Supreme Court of Canada (“SCC”) struck down the “promise doctrine” of Canadian patent law in favour of a test for utility of a far lower standard. In doing so, the SCC reversed a Federal Court of Appeal (“FCA”) decision finding AstraZeneca’s Canadian Patent No. 2,139,653 (“the ‘653 patent”) invalid for making certain promises which could not be demonstrated or soundly predicted at the time of filing. 
Under the SCC’s reasoning, the promise doctrine was not good law for two reasons: first, the doctrine improperly imports the disclosure requirement under s. 27(3) of the Patent Act into the utility requirement under s. 2,  and the doctrine improperly requires that every promised use of the invention be demonstrated or soundly predicted, lest the entire patent be held invalid. 
The SCC set out the correct approach for determining utility as a two-step analysis. First, the court is to identify the subject-matter of the invention as claimed in the patent. Second, the court must ask whether that subject-matter is useful – “is it capable of a practical purpose (i.e. an actual result)?”  A single use related to the nature of the subject-matter of the invention having a scintilla of utility is sufficient for satisfying the utility requirement.  This utility must be established by either demonstration or sound prediction as of the filing date. 
The Promise Doctrine is not Good Law: It is Punitive and Conflates the Utility Requirement with the Disclosure Requirement
Proponents of the promise doctrine assert that it serves the patent system by dissuading patentees from overplaying the utility of their inventions in order to obtain allowance,  and the doctrine thereby helps to maintain the quality and reliability of the patent database as a repository of useful teachings of inventions.
The SCC’s analysis, on the other hand, focused on the legislative origin of the utility requirement under s. 2 of the Patent Act, its interaction with other sections of the Act,  and on the current utility analysis incorporating the promise doctrine being out of line with other validity analyses in Canadian patent law.
First, the SCC criticized the promise doctrine as improperly importing the disclosure requirement under s. 27(3) of the Act into the utility requirement under s. 2 by requiring that any disclosed use be demonstrated or soundly predicted at the time of filing.  This doctrine, the SCC stated, “is an interpretation of the utility requirement that is incongruent with both the words and the scheme of the Patent Act”.  The SCC quoted Consolboard to draw a distinction between the utility requirement in s. 2, which is described as a “condition precedent to an invention”, and the disclosure requirement under s. 27(4) of the Act, which is independent of the utility requirement. 
Second, the SCC further criticized the doctrine as being “punitive” in that its operation may invalidate an entire patent if any one of the proposed uses of the invention does not pan out. This blanket invalidation of a patent is in contrast to claim-by-claim declarations of invalidity which result from other findings of invalidity (i.e. novelty, obviousness). Furthermore, the principle that one claim being invalidated does not affect the validity of other claims is codified in s. 58 of the Act. [31, 46, 51] Further, the SCC critizised the promise doctrine for directing courts to read both the claims and the disclosure to identify potential promises, rather than the claims alone, even in an absence of ambiguity in the claims.  Again, this practice is in contrast to in other validity analyses, where the focus is on the claims alone, and only considers the disclosure where there is ambiguity in the claims. 
SCC’s Correct Approach to Utility
The correct approach to the utility analysis, as set out by the SCC, is to be undertaken in line with its purpose – “to prevent the patenting of fanciful, speculative or inoperable inventions,”  and with an understanding that the subject-matter of an invention can be multi-faceted.  The SCC thus set out a two-step analysis:
- First, courts must identify the subject-matter of the invention as claimed in the patent. 
- Second, courts must ask whether that subject-matter is useful — “is it capable of a practical purpose (i.e. an actual result)?” 
A single use related to the nature of the subject-matter of the invention having a scintilla of utility is sufficient,  but a proposed invention cannot be saved by a use unrelated to the subject matter of the invention. For example, “it is not sufficient for a patentee seeking a patent for a machine to assert it is useful as a paperweight.”  As remains unchanged, the utility must be established by either demonstration or sound prediction as of the filing date. 
AstraZeneca Patent Saved by Single Useful Use
In a strikingly short four paragraphs, the SCC applied its new test for utility to the facts of the case of the ‘653 patent. The SCC identified the subject matter of the ‘653 patent that must be useful for the purposes of s. 2 as optically pure salts of the enantiomers of omeprazole. In the Federal Court (“FC”) decision, the FC had determined that:
. . . the subject matter of the ‘653 patent was optically pure salts of the enantiomers of omeprazole, described as novel compounds, having improved pharmacokinetic and metabolic properties and high stability to racemization in neutral and basic pH, a method to make them, and therapeutic uses. [emphasis in original] 
The SCC then summarily noted that the FC had held that it was soundly predicted by the relevant date that the optically pure salts of the enantiomer of omeprazole would be useful as a proton pump inhibitor (“PPI”) to reduce production of gastric acid. Since use as a PPI is appropriately related to the subject-matter of the ‘653 patent, the utility requirement was met. 
Although some members of the patent bar may rejoice at what is no doubt a pro-patent decision, the reasons provided by the SCC are conspicuously brief given the controversy surrounding the promise doctrine. For example, there is no discussion as to why it is justifiable for a patent application to make several unfulfilled promises of utility, especially in light of the sufficiency requirement as set out in the seminal Viagra case (Teva Canada Limited v Pfizer Canada Inc, 2012 SCC 60). In Viagra, the patent on the popular erectile dysfunction drug was invalidated for failure to comply with s. 27(3)(a) of the Act, which requires the patent specification to correctly and fully describe the invention. The patent in Viagra had claims covering a plethora of compounds, but did not specifically claim the only compound which was actually found to induce erections: sildenafil. This burying of the invention was considered to be against the patentee’s disclosure requirement, and resulted in the invalidation of the entire patent. However, a similar kind of burying the invention would be permissible under the new lens of utility, whereby a patent may disclose several potential uses, only one of which is the actual useful use.
Members of the public wishing to use the Canadian patent database as a repository of teachings need to know that the Supreme Court takes no issue with a patent describing several useless embodiments, so long as the patent discloses at last one embodiments which is useful. At the very least, the Supreme Court does not find this to be a problem with the patent’s utility – it remains to be seen whether other principles of patent law, such as sufficiency (re the Viagra case), will fill the void.
One wonders whether this decision also leave the door open for promise-like arguments to be made through s. 53 of the Patent Act, the provision which can be used to invalidate an entire patent for additions or omissions which are willfully made for the purpose of misleading. Section 53 has historically seen use in ownership and inventorship disputes, but : “this mischief may result in a patent being void under s. 53 of the Act, but the SCC explicitly nods to the possibility that Section 53 may be used to police overpromising. 
This decision is also timely given the recent NAFTA ruling which came down in favour of Canada and the promise doctrine. However, arguments in this case had been made long before the NAFTA ruling was released, and so the SCC did not directly address any of the countervailing arguments advanced in the arbitral NAFTA ruling.