Friday, February 7, 2014

Construal of the Promise of the Patent, Post-Plavix, Post-Eurocopter

Pfizer Canada Inc v Mylan Pharmaceuticals ULC (NOC) 2014 FC 38 Harrington J
            2,177,576 / celecoxib / CELEBREX

The only question in this NOC proceeding was how to construe the promise of the patent. This is only the second decision since the FCA’s important Plavix, decision, 2013 FCA 186 (leave to appeal to SCC granted 30 Jan 2014) which emphasized that the promise must be explicit (blogged here), and it is the first since the FCA’s subsequent more aggressive application of the promise doctrine in Eurocopter 2013 FCA 219 (blogged here). The case is an interesting test of whether the Plavix decision marks a new attitude to the promise doctrine, as the promise language in this case was somewhat ambiguous, and the issue might have done either way. In the end, Harrington J construed the promise of the ‘576 modestly, with the result that the allegation of invalidity was not justified.

The claims of the ‘576 patent at issue claimed celecoxib itself (Claim 4), which is a COX-2 selective NSAID, and celecoxib for treating inflammation or inflammation-associated disorders (Claims 8-13) [34]. It was conceded that celecoxib was useful in the treatment of inflammation and the key question was whether the patent also promised reduced side-effects in humans [4].

The argument that the patent promised reduced side-effects turned on two main points. One is that the background to the invention, as set out in the description, is that the previously known NSAIDs, which were not COX-2 selective, caused a variety of side-effects, and so the problem faced by inventors was to reduce those side-effects [53]: “Otherwise, the patent would merely be offering another in a large class of compounds in a crowded field” [54]. The difficulty with that argument is that even if reduced side-effects is a commercial goal of the inventors, achieving the goal is not required as a matter of the law of utility: “it does not matter how crowded a field may be. If Celebrex® was new, which it was, and useful in treating inflammation, which it is, then the invention is entitled to letters patent” [66]. As the SCC put it in Consolboard [1981] 1 SCR 504, 525, “it is sufficient utility to support a patent that the invention . . . affords the public a useful choice.” Consequently, while the inventors no doubt sought a product with reduced side-effects in order develop a commercially successful product, it does not follow that they would promise to achieve that goal. While Harrington J’s reasoning on this point strikes me as entirely sound, it is in tension with Pfizer v Apotex / latanoprost (NOC) 2011 FCA 236, in which the FCA held that the patent implicitly reduced side-effects in chronic treatment of glaucoma, simply because glaucoma was a chronic disease. It seems increasingly clear that latanoprost marked a high-water mark in the aggressive interpretation of the promise.

The other main argument turned, naturally, on the wording of the patent itself. The key statements were that the discovery [28]-[32]:

(1) provides a viable target of inhibition which more effectively reduces inflammation and produces fewer and less drastic side effects
(2) Compounds of Formula I would be useful for […] the treatment of inflammation in a subject
(3) The compounds are useful as antiinflammatory agents, such as for the treatment of arthritis, with the additional benefit of having significantly less harmful side effects.
(4) Such preferred selectivity may indicate an ability to reduce the incidents of common NSAID-induced side effects.

(1) is ambiguous, as “target” may imply a goal, rather than a result [56]. (2) clearly does not imply a promise of reduced side effects. (3) was the main phrase relied on by Mylan, but this could be construed as a possible benefit, and not a promised use [57]. This is consistent even with the old leading cases on the promise doctrine: so, in Alsop’s Patent (1907), 24 RPC 733, 753 (Ch), Parker J noted that a patent would not be invalid merely because “the patentee has gone on to detail the useful purposes to which such result can be applied.” With respect to (4), Harrington J noted that “The word ‘may’ connotes a possibility; maybe yes, maybe no. While it was hoped the selectivity would reduce side effects, no such claim was made” [65]. He therefore concluded that the specification as a whole did not promise reduced side effects, and he declined to address the question of whether that putative promise was met [60].

In coming to this conclusion, Harrington J also noted that a promise should not be inferred, citing the FCA Plavix decision [68]. He also relied on the presumption set out by Zinn J in his Fournier / fenofibrate (NOC) 2012 FC 741 [126] - [127] decision (blogged here) that:

Where that promise - that claimed utility - is clearly and unequivocally expressed by the inventor in the claims of the patent, then that expression ought to be viewed as the promise of the patent. Any statement found elsewhere should be presumed to be a mere statement of advantage unless the inventor clearly and unequivocally states that it is part of the promised utility.
If, as here, the claims are certain and unambiguous in stating the promise, then the disclosure should not be examined microscopically to find additional promises that are outside the scope of the inventor’s claimed monopoly.

On its face, Zinn J’s presumption applies only when there is a utility stated in the claims. In this case the utility was expressly stated in Claims 8 - 13, but there was no utility stated in Claim 1. Harrington J cited Zinn J as saying that “a utility not expressed in the claim portion of the specification ‘[…] should be presumed to be a mere statement of advantage unless the inventor clearly and unequivocally states that it is part of the promised utility’” [70]. This seems to imply a broader presumption that any statement in the disclosure should be presumed to be a mere statement of advantage – not only when there is a utility expressed in the claims. This seems to expand on Zinn J’s statement in fenofibrate, but it is broadly consistent with the FCA’s Plavix requirement that any promise must be explicit.

Finally, Harrington J dealt with the FCA Eurocopter decision by saying that “as noted by Mr. Justice Mainville, speaking for the Court of Appeal, at para 26, the advantage ‘was principally embodied in claim 1 of the […] Patent.’ Thus, I do not see two competing schools of thought in the Court of Appeal.” [71]. If I understand correctly, Harrington J seems to be saying that Eurocopter was a case in which the promise was found in the claim itself. With respect, I do not read the claim that way. Claim 1 described the invention and embodied the key elements which produced the promised advantage (reduced ground resonance), and so in that sense it embodied the advantage, but there was no explicit reference to reduced ground resonance in the claim itself. I doubt whether Eurocopter and Plavix are really reconcilable, and given that Harrington J has followed Plavix, it is not surprising that his interpretation of Eurocopter is strained. I should say that I think that he was right to follow Plavix, because that decision had a full discussion of the correct approach to construing the promise of the patent, while the approach was only implicit in Eurocopter.

In summary, even in the pre-Plavix era, this decision might very well have turned out the same way, as the promise language at issue was relatively weak. But it might also have gone the other way, and on the whole it suggests that the Plavix decision will indeed have a moderating effect on the construal of the promise. Of course this is all subject to whatever the SCC might say in the Plavix appeal.

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