On June 30, 2017, in AstraZeneca Canada Inc v Apotex Inc (AstraZeneca, 2017 SCC 36), the Supreme Court of Canada (SCC) rejected the Promise Doctrine as the correct approach to determine patent utility. This decision provides the much-needed guidance on how to determine patent utility, particularly in the pharmaceutical arts.
Section 2 of the Patent Act (Act), the source of the utility requirement, defines an invention as a “new and useful art, process, machine, manufacture or composition of matter” or a “new and useful” improvement thereof. The Federal Courts’ jurisprudence developed the Promise Doctrine, holding that if a patent promised a specific utility, only if that promise was fulfilled, could the invention have the requisite utility. The Promise Doctrine required the courts to identify the promise(s) by considering the claims and the disclosure.
The SCC rejected the Promise Doctrine as being excessively onerous in two ways: (1) “it determines the standard of utility that is required by reference to the promises expressed in the patent”; and (2) “where there are multiple expressed promises of utility, it requires that all be fulfilled for a patent to be valid”.
The SCC provided the following approach to utility:
identify the subject-matter of the invention as claimed in the patent;
ask whether that subject-matter is useful – is it capable of a practical purpose (an actual result).
The SCC noted that this usefulness must be related to the nature of the claimed subject-matter. It also noted that a scintilla of utility will do. Thus, a single use related to the nature of the subject-matter is sufficient; however, that utility must be either demonstrated or soundly predicted by the filing date.
The SCC nevertheless expressed the view that overpromising is a mischief and that the Act treats this mischief in multiple ways:
a disclosure which is not correct and full, or states an unsubstantiated use or operation of the invention, may fail section 27(3); and
overpromising may void a patent where such statements amount to an omission or addition that is “willfully made for the purpose of misleading,” under section 53.
In this case, the SCC found that AstraZeneca’s 2,139,653 patent is not invalid for lacking utility, because the Trial Judge found the claimed subject-matter – the optically pure salts of the enantiomer of omeprazole (esomeprazole) – to be useful as a proton pump inhibitor to reduce production of gastric acid.
Summary by: Junyi Chen