AstraZeneca Canada Inc. v. Apotex Inc. – Promise of the Patent: Not the yardstick against which utility is measured

The Supreme Court of Canada has ruled on the degree of utility required of patented inventions. The decision does away with the controversial “promise doctrine” that had evolved in Canadian jurisprudence, and brings Canadian patent law back in line with other jurisdictions on the issue of utility.

Canada’s Patent Act, along with the patent law of most other countries, requires that a patentable invention be useful for some purpose. This utility requirement has historically set a very low bar; any invention having a “mere scintilla” of usefulness will pass. The “promise doctrine” modified the utility requirement in certain circumstances. Under the doctrine, any statement in a patent that could be construed as a promise of a particular result was deemed to set a standard for the utility of the invention, which had to be met. In other words, if the patent promised a particular result, the invention had to deliver. Furthermore, the inventor had to know that the invention would deliver (or be able to predict that it would deliver) when the patent application was filed. If, on the filing date of the patent application the inventor did not know that the invention would so deliver, and could not soundly predict that it would deliver, the patent was deemed invalid.

The “promise doctrine” was unique to Canadian law and proved to be problematic for many patentees, particularly in the pharmaceutical industry, whose patent applications (which are typically filed worldwide) were not drafted with the peculiarities of Canadian law in mind. The validity of many patents was challenged under the doctrine, and some patents for otherwise useful inventions were struck down. The “promise doctrine” even resulted in a $500 million NAFTA arbitration claim against the Canadian government by pharmaceutical giant Eli Lilly, some of whose patents had been invalidated under the doctrine (thankfully for the Canadian taxpayer, Eli Lilly was not successful).

In AstraZeneca Canada Inc. v. Apotex Inc., (https://scc-csc.lexum.com/scc-csc/scc-csc/en/item/16713/index.do), Apotex alleged that AstraZeneca’s patent covering the drug NEXIUM was invalid, for the purpose of obtaining regulatory approval to market a generic version of the drug. Lower courts held that (i) AstraZeneca’s patent promised that the claimed compounds would provide a particular result, and that as of the filing date of the application, AstraZeneca had neither demonstrated nor soundly predicted that the compounds would so perform. In the words of the trial judge, the “yardstick” against which the utility of AstraZeneca’s patent was to be measured was the promises deemed to be made in its patent. Since AstraZeneca did not know whether such promises would be fulfilled at the time it filed its application, and could not soundly predict that they would be fulfilled, its patent was found to be invalid.

On appeal, the Supreme Court reversed the lower courts, finding that the “promise doctrine” is not good law. The Court found no support in the Patent Act for the idea that particular results allegedly promised in a patent set a unique standard of utility that must be met by the patented invention (especially since, in the absence of any such promise, a “mere scintilla” of utility is sufficient). The Court made it clear that promises found in patent are not the yardstick against which utility is to be measured. Rather, the utility requirement is met if the subject matter of the invention is capable of any practical purpose related to the nature of the subject matter.

The Supreme Court’s decision marks the end of a legal doctrine that generated considerable uncertainty in Canada’s patent system. The utility requirement of Canadian patent law is once again more or less in line with that of other jurisdictions. The decision is a major victory for patentees, particularly in the field of pharmaceuticals, where the majority of patent validity challenges under the “promise doctrine” were directed.

Summary prepared by Jaimie M. Bordman.