Canadian patents have utility requirements. A claimed invention must have some level of utility. A ‘mere scintilla’ of utility is all that the Patent Act requires.  However, where a patent contains an explicit promise of a specific result, the case-law has developed a requirement that this so-called ‘promised utility’ be demonstrated or soundly predicted as of the Canadian filing date of the patent application.

There has been much controversy over this ‘promise doctrine’ as well as the ‘heightened disclosure requirement’ that has been applied in the case of a sound prediction.  The controversy includes a NAFTA challenge by Eli Lilly scheduled to be heard later this year.

Today, the Supreme Court of Canada granted leave from the Federal Court of Appeal’s relatively short ruling in AstraZeneca v Apotex. In this case, Astra’s ‘653 patent was invalidated for lack of utility. The patent pertains to the compound esomeprazole sold in Canada as NEXIUM®.

The utility issue turned on the interpretation of the patent and specifically, whether the following statement in the patent disclosure amounts to a ‘promised utility’:

It is desirable to obtain compounds with improved pharmacokinetic and metabolic properties which will give an improved therapeutic profile such as a lower degree of interindividual variation. The present invention provides such compounds, which are novel salts of single enantiomers of omeprazole [emphasis added]

The dispute between the parties centered around whether the above-emphasized statement amounts to merely a goal, or a promise against which utility will be measured. At trial, the Court characterized this as a promise of the patent, finding that the evidence fell short of demonstrating or soundly predicting this promised utility.

In addition, the Court went on to consider the ‘disclosure requirement’ in so far as it is relates to sound prediction. The Court stated that the law in this area is “unsettled”, but found that the heightened disclosure requirement vis-à-vis sound prediction only applies in the case of a “new use” patent, if it exists at all. Accordingly, the Court concluded that the failure by Astra to disclose in its patent the studies it relied on at trial for demonstrated and soundly predicted utility was irrelevant in law.

On appeal, a unanimous panel of the Federal Court of Appeal upheld the trial judge’s inutility ruling. Astra argued that the trial judge had erred in law by misconstruing the promise of the relevant claims. In other words, Astra argued that utility, and indeed the promise, ought to have been considered on a claim-by-claim basis, consistent with the inventive concept of the claims (a matter relevant to obviousness) based on a purposive construction. The Court of Appeal disagreed.

First, the Court of Appeal agreed that utility is to be assessed on a claim-by-claim basis. Further, that some promises can impose utility requirements across all claims, while other promises may touch only a subset. This is, in every case, “a question of proper construction of the relevant claims.” However, there was no reversible error. According to the Court of Appeal, Astra had not asked the trial judge to construe the promise on a claim-by-claim basis.

Second, with respect to consistency with the inventive concept, Astra argued that because the inventive concept of the claims did not include an improved therapeutic profile, neither could their promise. The Court of Appeal rejected this argument on the basis that there was no support for it in the case law.

Finally, the Court of Appeal concluded that the promise was determined by way of purposive construction rather than a non-contextual construction.

Notably, the Court of Appeal did not address the issue of what, if any, disclosure requirement would apply in the case of a soundly predicted utility.

Undoubtedly, this case will be closely watched. The Supreme Court not long ago granted leave in another case raising issues about the appropriate legal standard for utility, whether the ‘promise doctrine’ is valid and how it should apply, as well as what, if any, disclosure requirements exist in the case of utility based on a sound prediction. That case was, however, never heard as Apotex withdrew its appeal on the eve of hearing by the Supreme Court.