Inventive Concept and the Promise of Utility Are Not Necessarily Coextensive

AstraZeneca Canada Inc v Apotex Inc / esomeprazole 2015 FCA 158 Dawson JA; Ryer, Webb JJA aff’g 2014 FC 638 Rennie J
            2,139,653 / esomeprazole / NEXIUM

The FCA’s brief Esomeprazole decision affirms a couple of important points that were raised in yesterday’s post (which I wrote before having read the FCA decision).

An initial, basic point is that the FCA affirmed Rennie J’s holding that the patent was invalid for failing to satisfy the promise of the patent, which was higher than the mere scintilla necessary to support a patent. As I remarked in my post on Rennie J’s decision, this shows that “the promise doctrine is alive and well post-Plavix FCA 2013 FCA 186.” This is not entirely surprising, as Plavix formally reaffirmed the promise doctrine, holding only that the promise must be explicit, but with the FCA’s affirmance in this case any thought that Plavix was the first step towards abandoning the doctrine entirely must now be laid to rest.

The FCA also stated that “[i]t is also now settled law that some promises can be construed to impose utility requirements across each of a patent’s claims, while other promises may touch only a subset of the claims,” citing Celecoxib 2014 FCA 250 (blogged here). While Rennie J in this case did not construe the promise on a claim-by-claim basis, the FCA held this was not an error in light of the evidence and submissions before him [6]. As noted in yesterday’s post, the distinction between overarching and claim-specific promises was applied by O'Reilly J in his Deferasirox decision.

AstraZeneca also argued that “the Federal Court erred by construing the utility of the claims in issue in a manner inconsistent with their inventive concept. AstraZeneca argues that because it is a fundamental rule of claim construction that a claim receives one interpretation for all purposes, there must be a unitary, harmonious understanding of the essential elements of the claim, inventive concept and utility” [10]. The FCA rejected this proposition as being unsupported by any jurisprudence. In my view, this holding is entirely correct. To elaborate on an example given in yesterday’s post, suppose a racemic compound is known to treat cancer though with side effects, and it is obvious to a skilled person that one of the enantiomers is therapeutically effective while the other is responsible for the side effects, but it is unusually difficult to resolve the enantiomers. If a patentee succeeds in resolving the enantiomers through inventive ingenuity and claims the therapeutically effective enantiomer, the claimed invention is surely patentable. But if the inventive concept and the promise of utility are coextensive, it would be held invalid; the enantiomer is useful, because it treats cancer (without side effects), but that was obvious to anyone. The reason the claim is valid is that the inventive concept, namely the method of separating the enantiomers, is distinct from the utility.