2,139,653 – esomeprazole – NEXIUM
Rennie J’s decision holding AstraZeneca’s esomeprazole patent invalid is interesting in several respects. Most importantly, Rennie J held that the effect of the SCC’s obiter remarks in Teva / sildenafil 2012 SCC 60 is to overturn previous FCA decisions holding that the factual basis for utility must be disclosed in the patent itself in all cases of sound prediction . On Rennie J's view, the disclosure requirement is now “limited to the context of ‘new use’ patents, assuming such a utility disclosure requirement exists at all” . On the other hand, his decision also shows that the promise doctrine is alive and well post-Plavix FCA 2013 FCA 186. This is not surprising, as the FCA affirmed the doctrine, and held only that the promise must be explicit. Rennie J’s decision makes no new law in this respect, though it gives some guidance as to what will be considered an “explicit” promise. On a third point, Rennie J also has an interesting analysis of what is meant by the “inventive concept” in the obviousness analysis. Ultimately, Rennie J held the ‘653 patent invalid solely for failure to meet the promise of the patent. This post will provide background and deal with the promise issue. Subsequent posts will deal with disclosure and obviousness.
The claims at issue, primarily claims 7 and 8 of the ‘653 patent , are compound claims to six specified salts of esomeprazole of high optical purity. “Esomeprazole,” is synonymous with the (-) enantiomer of omeprazole . As of the priority date, the skilled person would have known that omeprazole is a racemate, containing equal amounts of (-) and (+)-omeprazole; that omeprazole is a proton pump inhibitor (PPI) and is useful as an inhibitor of gastric acid secretion and for the treatment of gastric acid-related diseases; and that omeprazole is a very safe and effective drug .
In current Canadian law, a patentee will be held to every “promise” made in the specification, though failure to meet a goal, or “a hoped-for advantage of the invention,” will not invalidate the patent. Rennie summarized the difference between a promise and a goal as follows [117, his emphasis]:
In sum, promises are explicit and define guaranteed or anticipated results from the patent (depending on whether the promise is demonstrated or soundly predicted), whereas goals merely relate to potential uses for the patent.
There was considerable dispute over exactly how to characterize the putative promises, and of course over whether the statements in question were actually promises or merely goals, but in the end, Rennie J held that two promises were made respecting the claimed invention, namely
(1) that it was useful as use as a proton pump inhibitor (PPI); and
(2) that it had an improved therapeutic profile such as a lower degree of interindividual variation .
He held that the first promise was met , while the second was not , , and consequently the patent is invalid for lack of utility. (AstraZeneca argued that the second promise was, at most, of improved therapeutic profile, but that truncated promise would not have altered the outcome, as it was not met either .) Note that the promise (1), use as a PPI, is the same utility as omeprazole itself. Therefore it is clear that the claimed compound, high-purity esomeprazole, has sufficient utility to support a valid patent, and the patent was invalid solely because of the failure to meet the higher utility that was promised in the patent. Moreover, the elevated promise of improved therapeutic profile was found solely in the disclosure; the claims themselves were to the compound, with no mention of its properties or advantages. This case is therefore a clear example of the promise doctrine in action.
The second promise, which was determinative of invalidity, turned entirely on the interpretation of the following passage from the ‘653 patent [113, Rennie J’s emphasis]:
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.
Ultimately, Rennie J’s conclusion that this passage promised an improved therapeutic profile turned on the word “will” [119-20]. By way of contrast with this imperative language, he noted that in another case he found that “an object a clause beginning with ‘it is a particular object of the present invention to,’ merely described a goal that the patent strived to achieve” . As another example of language indicating a mere goal, “[h]ad the patent stated that such compounds 'may' or 'could' give an improved therapeutic profile, then the argument that such statements referred merely to a goal would be more compelling” .
If we accept the premise of the promise doctrine, that patentees intend to make promises of utility in the disclosure which will determine the validity of the patent, then Rennie J’s conclusion that the word “will” signifies a promise strikes me as sound as a matter of textual interpretation, and as being consistent with prior cases. As noted, while the FCA held that a promise must be explicit in its Plavix 2013 FCA 186, blogged here, it also clearly re-affirmed that if a promise is explicit, the patentee will be held to it. Since no patent ever says “I promise [heightened utility]," it is not surprising that affirmative language such as “will” is taken as a sufficiently explicit promise.
Of course, in my view it is wrong to suppose that a patentee ever intended to make promise in the disclosure, which is intended to disclose the invention, not define it: see my article “The False Doctrine of False Promise,” (2013) 29 CIPR 3 (draft version available here). But until the SCC addresses this doctrine, perhaps in the upcoming Plavix case, Apotex / esomeprazole illustrates a fairly straightforward application of the current state of the law relating to the promise of the patent.
To conclude, I should mention a couple of preliminary issues. One was the standing of AstraZeneca Canada, which Apotex challenged because there is no express license agreement between AstraZeneca Aktiebolag, the patentee, and AstraZeneca Canada, which distributed and sold NEXIUM in Canada [9-10]. Rennie J held that standing may be based on an implied licence , and that can probably be established solely by the fact that the patentee and the purported licensee are both joined before the court seeking recovery for infringement . In any event, an implied licence may certainly be inferred from the conduct of the parties, and the facts in this case clearly allowed such an inference . This holding strikes me as a straightforward application of Apotex Inc v Wellcome Foundation Ltd,  1 FC 495 (FCA), which had similar facts.
Rennie J also held that while an NOC proceeding is not res judicata in respect of a subsequent infringement action, which is well established, the doctrines of issue estoppel and abuse of process remain open . However, on the facts he held that it was not an abuse of process for AstraZeneca to shift its argument relating to the promise of the patent between the NOC litigation and the infringement action . Nor, while he found it “more problematic” , was AstraZeneca’s changed position regarding the moitivation of a skilled person to separate the enantiomers. On the whole, it seems that while issue estoppel and abuse of process remain open, they will not be lightly invoked to constrain a patentee from changing its litigation strategy between the NOC proceeding and the infringement action.
Finally, I’m a bit late with this post, as I had an enforced long weekend, after storm Arthur left me (and most of Fredericton, NB) without power for three days.