Monday, June 28, 2021

Direct Infringement and Swiss-Form Claims

Hoffmann-La Roche Limited v Sandoz Canada Inc 2021 FC 38 Manson J

2,667,654 / 2,709,997 / pirfenidone / ESBRIET / NOC

Roche’s 654 and 997 patents at issue in this NOC proceeding relate to the use of pirfenidone in the treatment of idiopathic pulmonary fibrosis [IPF]. As discussed in my last post, Manson J held that the asserted claims of both patents were invalid for obviousness and as being methods of medical treatment. This post will address Manson J’s construction of the Swiss-type claims.

The 654 patent claimed a dose escalation regimen, while the 997 patent claimed full dose treatment of a patient who had exhibited liver abnormality after initial treatment. The details of the claims don’t matter for present purposes. Both patents had three distinct claim types [95]–[96]:

            1) “German-style” — “Use of [drug] for treatment of [disorder]

2) “Swiss-style” — “Use of [drug] in the manufacture of a medicament for treatment of [disorder]

3) “Product for use style” — “[Drug] for use in the treatment of [disorder]

Sandoz argued that “Swiss-style claims do not apply in Canada and are properly construed as ‘use’ claims where the alleged invention resides in the use and not in the manufacture or composition of the medicine” [96]. Roche apparently argued that there is a substantive distinction between the claim types, such that Sandoz would be a direct infringer of the Swiss-style claims. (Manson J did not expressly state Roche’s argument.)

Manson J rejected Roche’s approach, saying it “seeks a finding of claim form over substance. In doing so, it obscures the proper approach to claims construction. As discussed above, the claims construction exercise emphasizes a purposive construction” [97] (original emphasis); and similarly, the case law “supports an approach to claims construction which values substance over form” [107].

With respect, it’s not quite right to say that a purposive approach focuses on substance over form—though in saying that, I have to admit that in a previous post on the UKSC decision in Warner-Lambert v Actavis [2018] UKSC 56, I made comments about Swiss-form claims that were very much along the same lines as those as Manson J in this case, so the extent that I am disagreeing with Manson J’s analysis, I am also disagreeing with myself. In any event, the principles of statutory interpretation apply to claim construction by virtue of the Interpretation Act: Whirlpool 2000 SCC 67 [49(e)]. Those principles require consideration of text, context and purpose: Canada Trustco 2005 SCC 54 [10]; Canada v Utah 2020 FCA 224 [9]. Purpose is one consideration, but primacy is given to the text, both in statutory interpretation generally—“When the words of a provision are precise and unequivocal, the ordinary meaning of the words play a dominant role in the interpretive process”: Canada Trustco 2005 SCC 54 [10]— and in claim construction in particular, where “The primacy of the language of the claims was emphatically affirmed in the celebrated case of Catnic Components Ltd. v. Hill & Smith Ltd., [1982] R.P.C. 183 (H.L.)”: Whirlpool 2000 SCC 67 [40]. Thus the purpose and context inform our understanding of the text, but the focus is on the text itself. A purposive analysis may in principle result in some part of the text effectively being read out of the claim, but this is rare in practice and is only done after an explicit essentiality analysis, which was not at issue here.

The main purposive consideration relied on by Manson J was to the effect that the inventive concept was the dose escalation regime: “there is nothing novel about the manufacture or composition of pirfenidone to treat IPF in this case, but only a new dosing regimen of pirfenidone for use in the treatment of IPF” [103]; “The alleged invention in this case resides in the use of pirfenidone, whether in the context of the 654 or 997 Patent, and not in the manufacture or composition of pirfenidone, a known compound” [97]. That’s true enough, but it doesn’t imply that the claim should be construed as a use claim. Manson J’s analysis almost seems to imply that a patentee is restricted to a claim form that directly reflects the inventive concept, and that has never been the law. A claim that does not encompass the inventive concept will normally be invalid for obviousness or anticipation, but there is no general prohibition on adding other elements that narrow the scope. For example, if an inventor discovers a new medical use for a known compound, the inventive concept lies in the discovery of the use. While the patentee will normally claim the use to treat the disorder, the patentee may also claim the product for use in various forms, such as a tablet, capsule, injectable form and a form for parenteral administration, even though none of the various forms involves an additional inventive step. Manson J also referred to the experts’ understanding of the claims expert understanding of the claims as relating to a dose escalation regimen [91], [97]. In effect, they understood the claim as being addressed to the inventive concept. But claim construction is for the court, not the experts, and the fact that a scientific expert ignored the text does not mean that the court should do so.

Why does it matter? Two substantive points are engaged. The Swiss-form claim was originally developed to avoid the European prohibition on patenting of methods of medical treatment. A Swiss claim is to the use of the drug “in the manufacture of a medicament,” and since the physician who prescribes a drug does not manufacture it, on its face, physicians are excluded from the scope of infringement. The rationale currently offered by Canadian courts for the prohibition on patenting methods of medical treatment is to ensure that the patent does not impede the physician in their treatment of their patients, so if Swiss-form claims were successful in excluding physicians from the scope of the claim, it would certainly be a point of substance. However, as the EWCA pointed out in Warner-Lambert v Actavis [2015] EWCA Civ 556 [54], the Swiss-form claim is probably not effective in excluding doctors from the scope of the claim: “As the claim is a process claim [under s 60 of the Patents Act 1977], its direct product, the medicine, is an infringement, and all those who use or dispose of the product will infringe.” The same appears to be true in Canadian law, in light of the Saccharine doctrine: see Hospira 2018 FC 259 [328]. The basic problem is that if a Swiss-form claim is infringed only by the actual manufacturer, then a generic could escape infringement of a Swiss claim by manufacturing abroad (as was argued, and rejected, in Hospira); but since Swiss claims are construed as encompassing the product of the patented process, it follows that the sale and use—including by physicians and patients—will also infringe. The lesson here seems to be that the problem of patentability of methods of medical treatment is not going to be solved by clever claim drafting.

But there is another aspect to Swiss claims. If construed as a claim to the process of manufacture and not solely as a use claim, then the manufacturer would be a direct infringer. This is entirely aside from the issue of whether those who use the product are infringers as well. In this case, the result of Manson J construing the Swiss claim—on its face a process claim—as a use claim, is that even though Sandoz evidently used the process, by manufacturing a medicament for the claimed purpose, it was not liable for direct infringement of the Swiss claim, “as it does not and will not use the Sandoz Products in the treatment of IPF” [108]. That is, the original purpose of Swiss claims was to exclude physicians from the scope of the claim, so that only the manufacturer would be a direct infringer. If Swiss claims are construed as use claims, the result is that the manufacturer is excluded from the scope of direct infringement, while physicians are encompassed—effectively the opposite of the original intent.

Roche therefore was confined to an argument in indirect infringement, which requires (i) direct infringement; (ii) inducement by Sandoz; (iii) knowledge by Sandoz. The direct infringement is that of the physicians and patients, and the knowledge requirement is only that Sandoz knows that its actions will result in direct infringement. The first and third elements will normally be readily established in any case in which the generic makes and sells a product with indications for the specified use, as happened in this case: [142], [123]. The real difference between direct and induced infringement lies in the second requirement. The main issue in this case, as is typical, is whether prescribing physicians read and are influenced by the Product Monograph which directs an infringing use [124]–[141]. If the Swiss claims were construed as process claims, then Sandoz would have been a direct infringer, and it would not have been necessary for Roche to establish that the physicians read and were influenced by the PM. Because the the Swiss claims were construed as use claims, Roche was required to prove that physicians do actually read the Sandoz PM. In this case, Roche was able to establish that at least some phyusicians would consult the Sandoz PM [140], so indirect infringement was established, albeit with an extra evidentiary hurdle.

So, construing the Swiss claims as use claims means that a generic that made and sold a drug intending it to be used for the patented purpose, and which was in fact used for the patented purpose, will not be liable unless the patentee can establish that the physicians read and were influenced by the generic PM. If the facts establish that physicians read the brand PM and rely on their knowledge that the generic product is equivalent, without actually being influenced by the generic PM, the generic will be able to make and sell the drug for the patented use.

As a practical matter, the patentee is usually able to prove that the physicians were influenced by the generic PM, so the result is only to add cost and complexity without changing the result. This would be acceptable if there were some good reason of policy or principle for enabling the generic to escape liability if the physicians rely on the brand PM instead of the generic PM; but I have considerable difficulty seeing any good reason for restricting the scope of infringement in that manner. The requirement of influence makes good sense when the product has a substantial non-infringing use, to ensure that the defendant is not prevented from selling the product for non-infringing uses: see generally Contributory Infringement in Canadian Law (2020) 35 CIPR 10. But why should a generic be permitted to sell a product which it specifically intends should be used to infringe, and which is in fact used to infringe, simply because the physician relies on the brand PM and equivalency, instead of reading the generic PM? In effect, construing the Swiss-type claim as a use claim introduces a substantive limitation on the scope of infringement. Perhaps there is some good policy reason for it, but if so, it should be directly articulated. I have a draft paper “Is 'But For' Causation Necessary to Establish Inducement?” arguing that the law of inducement should be clarified to avoid this result. Unless it is, the construction of Swiss-form claims will remain significant even if the confusion over patentability of methods of medical treatment is eventually resolved.

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