Should Experts Be “Blinded” as to the Infringing Device When Construing the Claim?

Teva Canada Innovation and Teva Pharmaceutical Industries Ltd v Apotex Inc (NOC) 2014 FC 1070 Gleason J
            2,232,310 / rasagiline / AZILECT

In this NOC decision, which turned entirely on claim construction, Apotex’ Apo-rasagiline product was found not to infringe Teva’s ‘310 patent. The main point of legal interest is Gleason J’s holding that if an expert is “blinded” as to the nature of the putatively infringing product when carrying out their claim construction, this is a reason to prefer that evidence over the evidence of an expert who is not so blinded.

The ‘310 claims a pharmaceutical composition comprising rasagiline and at least one alcohol selected from the group consisting of “pentahydric and hexahydric alcohols” [7]. It was undisputed that the term “pentahydric” refers to five hydroxyl, or “-OH” groups, and that the term “hexahydric” refers to six hydroxyl groups [20]. So, for example, mannitol is pentahydric:

Apotex’s product comprised rasagiline and an alcohol, and the sole question was whether that alcohol was pentahydric or hexahydric. While the exact alcohol used by Apotex was redacted (with the redaction to be removed once Apotex’ NOC is issued) [5], the problem can be understood if we suppose Apotex’ product contained maltitol:

Apotex’ experts opined that in naming an alcohol, all the -OH groups in the molecule should be counted, while Teva’s experts were of the view that only the groups on the alcohol moiety should be counted. So, on the former view maltitol would be a nonahydric alcohol, and on the latter view it would be pentahydric.

Gleason J accepted the view of Apotex’ experts, primarily - or at least "firstly" - as a matter of textual construction of the specification. In particular, the specification uses the term “alcohol” to refer to the entire molecule to be used in the composition, not just the alcohol moiety, and it uses the term “pentahydric or hexahydric” to modify the term “alcohol,” thus implying that all the -OH groups in the molecule must be counted, not just those on the alcohol moiety [89]-[93].

A second reason that Gleason J preferred the evidence of Apotex’ experts is of more general interest. Apotex’ experts had been provided with the ‘310 patent and asked to construe it, and only subsequently were they provided with Apotex’ ANDS and asked to opine as to whether Apo-rasagiline fell within the claims [43]-[46]. Teva’s experts, on the other hand, construed the ‘310 patent with the allegedly infringing substance in mind [34]-[42]. Gleason J held that the way in which they had been instructed was a reason to prefer the evidence of Apotex’ experts [94]. (Though she did not suggest it was a determinative reason.)

As Gleason J acknowledged [96], this raises the tension between the principle that “the construction exercise [should] be uninfluenced by concerns over infringement or invalidity,” and the competing principle that in construing claims "it is essential to see where the shoe pinches” Nokia v Interdigital [2007] EWHC 3077 (Pat) [25], quoted with approval in Qualcomm v Nokia [2008] EWHC 329 (Pat) [7], quoted with approval by Hughes J in Shire Biochem 2008 FC 538, [22] (and see 2009 FC 991 [88]; 2009 FC 676 [82]). Gleason J said that

However, the decision in Shire Biochem does not stand as authority for the proposition that it is proper to construe a patent with the infringing substance in mind, but, rather, only for the common sense notion that to be useful evidence and arguments in a case must be directed toward the issues that arise.

This is not quite right. What Floyd J said in Qualcomm, quoted with approval by Hughes J in Shire Biochem, is that

It is often said that a patent specification should be construed without reference to the infringement. Yet one cannot sensibly identify the point of construction without understanding what it is about the alleged infringement which is said to take it outside the claims.

So, when the claim calls for A, and the allegedly infringing device requires B, “the right question is . . . whether in its context in the specification the skilled man would appreciate that A in the claim encompassed B” (Qualcomm [25]). This necessarily requires focusing on the allegedly infringing device. Similarly, in Technip France SA's Patent (2004) RPC 46, quoted in Shire Biochem, Jacob LJ remarked that “in most sensible discussions of the meaning of language run on the general lines `does it mean this, or that, or the other?' rather than the open-ended `what does it mean'?” In Nokia, Pumfrey J prefaced the quoted remark with the statement that “it seems sensible to turn to the [allegedly infringing product] to identify the points of construction that arise” [25]. He specifically directed the parties to serve statements of the case identifying the relevant aspects of the allegedly infringing product for the experts to focus on in construing the claims, and he indicated that such statements are “essential” [26], at least in a complex case.

Two SCC decisions cited for the proposition that claim construction is independent of validity and infringement are Whirlpool 2000 SCC 67 and Sanofi 2008 SCC 61. In Whirlpool the Court said that “Claims construction is antecedent to consideration of both validity and infringement issues” [43]. This may be taken to say that construction should not be influenced by concerns over infringement or invalidity, but it does not say that claim construction should be undertaken without reference to the infringing product. In holding that the report of the experts who had been “blinded” should be preferred, Gleanson J cited Rennie J’s holding to the same effect in Omeprazole 3 2014 FC 638, [321]. Rennie J held that the “blinded” experts “had mandates that allowed them to opine on the state of the art, in the words of the Supreme Court of Canada, ‘viewed without any knowledge of the alleged invention as claimed’ (Sanofi-Synthelabo Plavix, at para 67).” But that statement in Sanofi was made in the fourth step of the Windsurfing / Pozzoli test for obviousness

(4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?

What this is saying is that the obviousness inquiry must be undertaken without the benefit of hindsight. Claim construction is step (2) of the test, and Sanofi does not say that claim construction should be undertaken without reference to the infringing product.

Apart from these authorities, I see a danger in ignoring the infringing device. Suppose that almost all alcohols were simple linear chain molecules, so that there is normally no difference between counting -OH groups in the alcohol moiety and counting them in the molecule as a whole. If asked the general question of how to define a pentahydric alcohol, a skilled person might say “count the -OH groups in the molecule.” But if then presented with an unusual alcohol with two distinct parts, the skilled person might well say “Well, I never thought of that – of course I meant that when there are two parts to the molecule, you should count the -OH groups on the alcohol moiety.” Imagine trying to give legal advice to a client who insisted on asking “what are the requirements for a valid patent,” while refusing to disclose her invention, and who then insisted on holding you to your original definition after revealing the peculiarities of her own invention.

I take the point that claim construction should not be tendentious. But it seems to me that ignoring the infringing device in claim construction can also be misleading. Either course has its risks. Rather than preferring the evidence of experts who have been blinded, perhaps it would be better to recognize the problem of tendentious testimony on the one hand, and misdirected evidence on the other.

Finally, Gleason J remarked that

[96] Teva could easily have directed its experts’ attention to these issues by posing the question whether the terms “pentahydric or hexahydric alcohols” as used in the 310 Patent would connote a molecule or a moiety to the skilled person, without alerting the experts to the fact that the potentially infringing substance was [redacted].

I don’t find this persuasive. I agree that this would have properly directed the experts’ witness to where the shoe pinches, but I’m not sure this type of instruction is any better than revealing the allegedly infringing molecule itself. The experts knew that all the alcohols specifically mentioned in the specification were linear chain alcohols (mannitol, sorbitol and xylitol), and an expert instructed to consider whether the term connoted a molecule or a moiety could readily have inferred that the infringing substance had two distinct moieties, which would defeat the purpose of the blinding. More importantly, this approach demands an excessive degree of foresight from counsel; how can counsel, who are not normally themselves persons skilled in the art, know in advance which aspects of the allegedly infringing product are relevant to the claim construction? How would they known to present the molecule / moiety distinction before having an opinion from an expert that it was relevant? Perhaps in this case the particular point might have been obvious to a pharmaceutical litigators of ordinary skill, but as a general matter we cannot presume that litigators will know “where the shoe pinches” before they are told by experts.