Thursday, August 18, 2022

What Is the Date for Assessing Sufficiency?

Pharmascience Inc v Bristol-Myers Squibb Canada Co 2022 FCA 142 Locke JA: de Montigny, Monaghan JJA affg 2021 FC 1 Zinn J FC Selection

2,461,202 / 2,791,171 / apixaban / ELIQUIS

My previous post addressed issues of selection patents raised by this decision. This post discusses the insufficiency attack on the 202 patent, and concludes with a brief discussion of the 171 patent, which reveals another failed attempt to give independent effect to overbreadth as a ground of attack. As described in my last post, the patents in suit relate to the anticoagulant compound apixaban which is used in treating thromboembolic disorders, including stroke. The 202 patent claims the compound apixaban as such, as well as its use in the treatment of thromboembolic disorders [4]. The 171 patent claims various formulations of apixaban. Only validity was at issue.

Insufficiency attack on the 202 patent

Pharmascience argued that the 202 patent was invalid for insufficiency because it did not indicate that the focus of the invention was apixaban at either the filing date or the publication date [22]. Apixaban was merely one of hundreds of examples, and the claims focusing on it were not introduced until shortly before the patent issued [22].

The answer to this argument is that it is the validity of the granted patent that must be considered. Saying that validity on one ground or the other is assessed as of a particular date does not change that. So, when we say that the claims must be novel as of the claim date, we do not mean that the claims as they existed at that date must be novel, but rather that the claims in the granted patent must claim subject-matter that was novel as of the claim date [31]. The same applies to sufficiency: it is the specification of the issued patent that must adequately disclose the invention [32]–[33]. If we say that sufficiency is assessed as of the filing date (of which, more below), that means that the specification as granted must enable a person skilled in art to make the invention in light of their common general knowledge as of the filing date.

Consequently, this point should have been framed as an added matter objection: “[t]he real debate here should be whether the addition of claims specific to apixaban introduced new matter to the specification of the 202 Patent that could not reasonably be inferred from the application as filed” [37]. It was problematic to raise this on appeal without having raised it at trial [37], but in any event, Locke JA noted that an added matter objection probably could not be sustained, as apixaban was specifically described in Example 18 and that would seem sufficient to support the introduction of claims thereto [37].

That all makes sense. But the decision also has a relatively lengthy discussion of the appropriate date for assessing sufficiency. Pharmascience relied on the decision of Hughes J in Zoledronate 2013 FC 283 [179]–[188], which implied that the correct date is the publication date [23]. Locke JA discounted the Zoledronate decision for various reasons (eg the discussion was obiter), without actually saying it was wrong and without specifically stating the law as to the appropriate date for assessing sufficiency [26]–[28]. For example, Locke JA noted that Hughes J did not address the view expressed by MacKay J in Merck v Apotex 59 CPR(3d) 133 (FCTD) that the date of issue is the appropriate date for assessing insufficiency [28], but only by way of indicating that Hughes J’s analysis was incomplete.

This seems a bit strange because, as indicated in my post on Zinn J’s decision, I thought the point was settled in Idenix v Gilead 2017 FCA 161 [46] affg 2015 FC 1156. In that case, the patentee, Idenix, had not actually synthesized any of the claimed compound as of the filing date: see here. Gilead, therefore, made a classic “how to make” insufficiency argument, and Annis J held that the disclosure was not sufficient to allow a skilled person to synthesize the compounds, and held the patent invalid for that reason. This was even though, by the time of trial, the claimed compound could be synthesized by three different pathways [FCA 46]. I’ve taken a look through Annis J’s (very long) decision, and it is not clear to me what date he took to be the appropriate date; the focus of the discussion is on showing that “retrosynthetic analysis”, based on the specification plus routine experimentation, was not sufficient to enable a skilled person to make the claimed compounds. The first public disclosure of how to make the compounds was in January 2005 [FC 501], so the patent would have been sufficient as of that date, at least if the skilled person were taken to be aware of that public disclosure. The 191 patent at issue had a filing date of June 2003 and a publication date of January 2004, so the patent would have been insufficient as of those dates, but sufficient as of the date of issue. This implies that we can at least rule out the date of issue as the appropriate date for assessing sufficiency.

The FCA affirmed the finding of insufficiency saying:

[46] Though reversed on other points, this Court held in [Viagra] 2010 FCA 242 at paragraph 79. . . that courts must “determine whether the disclosure was sufficient as of the date of filing. As a result, anything which occurred subsequent thereto is of no relevance.” In my view, Idenix’s argument reflects the benefit of hindsight rather than the knowledge of the skilled person at the relevant date.

This clearly indicates that the appropriate date is the filing date, though the result is consistent with using the publication date.

I find it peculiar that, in this case, Locke JA did not mention the FCA decisions in either Idenix or Viagra. It is true that neither of those cases analyzes the issue—the statements of the appropriate date are conclusory—while the FC decisions of MacKay J Merck v Apotex and Hughes J in Zoledronate do have an extended discussion. But still, the express statements by the FCA are directly on point, even if not fully reasoned.

I suspect Locke JA chose to avoid Idenix or Viagra because their endorsement of the filing date sits uneasily with his response to Pharmascience’s argument:

[33] [Pharmascience] notes that subsection 27(3) identifies the requirements of the “specification”, and argues that subsection 27(2) indicates that it is the specification as filed that must meet those requirements. However, such an argument does not withstand scrutiny. Firstly, it would effectively read out subsection 27(6), which contemplates amendments to bring the application into compliance with the sufficiency requirements. Secondly, a similar argument would seem to apply to the requirements for novelty (the opposite of anticipation) and inventiveness (the opposite of obviousness). Sections 28.2 and 28.3, which address these issues, both refer to requirements for “[t]he subject-matter defined by a claim in an application for a patent.” PMS’s focus on the specification as filed for determining sufficiency would also imply a focus on the claims as filed for anticipation and obviousness, since the relevant provisions mention “a claim in an application”. I can see no reason that the approach that PMS urges for sufficiency would not apply similarly to anticipation and obviousness.

I’ll take the second point first. It is perfectly clear that novelty and inventiveness are assessed as of the claim date. But it is the claims as granted that must have been new and inventive as of the claim date; there is no requirement that the claims as they existed as of the claim date must be new and inventive. The same point applies to sufficiency. The specification as granted (including any amendments as per 27(6)) must have been sufficient at the relevant time (whenever that is). That means that in assessing the sufficiency of the specification as granted, we must consider whether it would have allowed the skilled person to practice the invention at the relevant date, without the assistance of new techniques or knowledge that emerged after that date. Turning to the first point, saying that the relevant date for sufficiency is the filing date does not read out 27(6). To say that the relevant date is the filing date does not mean that it is the specification as it existed as of that date that must be sufficient, just as saying that the relevant date for utility is the filing date does not mean that it is the claims as they existed at that date that must claim useful subject-matter. It simply means that in assessing the sufficiency of the specification as granted, common general knowledge arising after the filing date cannot be taken into account. (I note also that while 27(6) permits amendments, that is subject to 38.2, which only permits the addition of matter that can reasonably be inferred from the specification as filed. Consequently, I suspect it would be difficult, and perhaps impossible, to amend a specification that is insufficient as of the filing date so as to render it sufficient at some subsequent date. But that is an aside.) So, the fact that claims can change post-filing does not mean that the relevant date for assessing novelty is post-filing; similarly, the fact that the specification may be amended post-filing does not mean that the relevant date for assessing sufficiency is not the filing date.

At the end of the day, I’m inclined to think that the appropriate date for assessing sufficiency is indeed the filing date. But I suppose the fact that the FCA in this case ignored Idenix and Viagra means that the point should now be considered open.

171 patent

The 171 patent relates to a formulation of apixaban with, inter alia, a specified particular size. Locke JA affirmed Zinn J’s holding on the facts that it was not obvious-to-try [39]–[59]. Pharmascience also argued that the patent was invalid for ambiguity on the basis that the method for determining particle size was not specified, and different methods could give different results. Locke JA dismissed this argument, pointing out that the specification did describe a particular measuring method and a skilled person would understand this to be the method to use [66].

Finally, Pharmascience made an overbreadth attack. In Seedlings 2021 FCA 154 (blogged here) the FCA affirmed that “overbreadth remains a proper ground of invalidity” [50]. Consequently, we are now seeing overbreadth raised regularly as a ground of invalidity. But parties attacking the validity of a patent have struggled to find an approach to overbreadth which gives it any independent force. This case is another example. Locke JA remarked that “The nature of [Pharmascience’s] argument on overbreadth of the 171 Patent is not entirely clear” [69]—which is not entirely surprising, given that the concept of overbreadth itself is not clear. In any event, Locke JA’s discussion was brief, so I’ll just note that Locke JA, after dismissing it on the facts, indicated that the attack “would seem to relate to the sufficiency of the 171 Patent, rather than overbreadth” [71]. Another attempt to give some effect to overbreadth as an independent ground of invalidity has failed.

UPDATE: see my follow-up post on the date for assessing sufficiency.

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