Skepticism Regarding I G Farbenindustrie Test for Selection Patents

Bristol-Myers Squibb Canada Co v Pharmascience Inc 2021 FC 1 Zinn J

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

This decision consolidated four actions concerning the 202 patent, which claims the compound apixaban and its use in treating thromboembolic disorder, including stroke [2], [27], and the 171 patent, which claims various formulations of apixaban[2], [114]. The decision raises several legal issues, though largely as a result of some “creative” submissions by the defendants [125]. The most important point is that Zinn J expressed considerable skepticism regarding the continued vitality of the I G Farbenindustrie test for selection patents. Zinn J addressed the 202 patent first and then the 171 patent. I won’t cover every issue, but only those that caught my eye.

Date for assessing sufficiency

The first attack on the 202 patent was based on insufficiency. There was some discussion of whether the date for assessing sufficiency is the date of filing or the date of publication [36]–[42]. I’ll note that there has indeed been some debate in the case law on this issue, but the point was settled in Idenix v Gilead 2017 FCA 161 [46], holding that the correct date is the filing date, in a case that was crucial to the result. (I’d suggest that while Idenix ruled out the publication date, there remains an open question as to whether it should be the claim or the filing date, as that distinction was not at issue in Idenix—I’d argue that it should be the claim date, but that’s for another day.) Idenix was not cited by Zinn J, presumably because it was not cited to him, and consequently he appears to have considered the publication date to be the relevant date [49].

In any event, so far as I can tell, nothing turned on this point. As both filed and published the application claimed 10¹⁰⁰ compounds, and it was only just before issuance that the claims were narrowed to one compound, namely apixaban [37]. The defendants apparently argued the patent was insufficient because it did not enable all 10¹⁰⁰ compounds to be made [37]. That is, sufficiency had to be assessed in terms of the document as it existed at the relevant date (whatever that date might be). That is certainly a very creative argument, but. . . no, “The test for sufficiency is whether [the skilled person] is in a position to work the invention. The invention is that claimed in the patent, and until it is issued, there is no patent” [49]. That must be right — if it weren’t almost every granted patent would be invalid, because claims are routinely amended during prosecution in response to objections by the examiner, which necessarily takes place after filing. If anticipation, utility and obviousness all had to be assessed as of the claim date or filing date, then amendments to the claims could never cure any objection.

Studies demonstrating utility need not be referenced in the patent

The defendants also argued that the patent was invalid for lack of utility because the study demonstrating utility must be referenced in the patent. Zinn J rejected this proposition, relying primarily on statements by the SCC in Sildenafil 2012 SCC 60 [39]–[40] and AstraZeneca 2017 SCC 36 [58]. I’ll add that Gleason J (as she then was) reviewed the authorities in Lilly v Apotex 2015 FC 1016 [138]–[141]. She pointed out that the FCA authorities supporting such a requirement were obiter, and there are many cases to the contrary, and she therefore concluding that “the weight of authority is to the effect that the evidence of demonstrated utility need not be referenced in the patent for the patentee to rely on it” [142]. I think this point can now be considered settled, though it would certainly be desirable to have it addressed by the FCA to remove any lingering doubt.

A genus too large to think about does not anticipate

The most interesting issue was an anticipation attack based on 2,349,330, which disclosed and claimed a large class of compounds that were potentially useful in the treatment and prevention of thromboembolic disorders [79]. The class is very large. One of the experts for Sandoz did a calculation of the number of compounds disclosed and came up with “Some number that is just larger than I can think about.” He agreed that it was “more possibilities than stars in the universe” [80]. On the evidence provided by Sandoz’s experts, the class encompassed apixaban [77], but did not specifically disclose it, or describe how to make it [82]. On this evidence, Zinn J had no difficulty in concluding that the 330 patent did not anticipate apixaban [83].

Nor was apixaban obvious over the 330 patent, as only a small percentage of the disclosed compounds would actually be effective in treating thromboembolic disorders, and identifying which would involve “complex, time-consuming, unpredictable research” [87]. Obviousness-type double patenting failed for the same reason: [96]–[97].

IG Farbenindustrie test doubted

Apixaban is therefore a classic selection over the 330 patent. Significantly, it was only after finding that apixaban was neither anticipated nor obvious over the 330 patent that Zinn J turned to question of selection patents as such and the three-part test set out in IG Farbenindustrie (1930), 47 RPC 289 (Ch) 322-23, that was approved in Sanofi 2008 SCC 61 [9]-[11]. The factors, in summary, are: (1) a valid selection must possess some substantive advantage over the genus; (2) all of the selected members must possess the advantage; (3) the advantage must be peculiar to the selected group. Zinn J held that these three propositions are “not a stand-alone basis to find a selection patent invalid,” relying on the express holding to that effect in Olanzapine 2010 FCA 197 [33] where the FCA stated that an assessment of whether the IG Farbenindustrie conditions has been met “does not constitute an independent basis upon which to attack the validity of a patent” [104]. Despite this holding by the FCA, the IG Farbenindustrie conditions continue to resurface as an independent ground of attack, most recently in Lilly v Mylan 2020 FC 816, discussed here.

Zinn J’s contribution to this debate was to go back and quote from the explanation for these factors given by Maugham J in IG Farbenindustrie itself [100]. In the passage quoted by Zinn J, Maugham J specifically connected the first and second factors to standard grounds of attack, namely utility and insufficiency. The explanation given by Maugham J for the third factor is somewhat more obscure, and also more controversial, as it was specifically criticized in Dr Reddy’s [2009] EWCA Civ 1362 [39]. I suspect that the third factor was an imperfect attempt to avoid the problem of arbitrary selection, which is properly treated as an aspect of non-obviousness. I might also add that I am not at all convinced that the first and second factors are properly related to utility, as Maugham J indicated. But the important point here is that Maugham J did explain the factors he set out in terms of the traditional grounds of invalidity. As I read it, Maugham J considered these factors to be a helpful way of stating the standard principles in the context of a selection patent, and not as an entirely new ground of attack. I agree therefore, with Zinn J’s observation that for Maugham J, and for Rothstein J in Sanofi referencing Maugham J’s analysis, “a failure to meet his three propositions regarding selection patents does not invalidate the patent; rather its validity is subject to the usual grounds relevant to any patent” [101]. I am very pleased to note that Zinn J also cited my blog post, Time to Relegate IG Farbenindustrie to the Dustbin of History, in which I pointed out that the SCC in Sanofi did not apply the IG Farbenindustrie as an independent ground of invalidity on the facts, but rather relied on the standard grounds of anticipation and obviousness, as Zinn J did in this case. That is why it is significant that Zinn J addressed anticipation and obviousness before turning to the IG Farbenindustrie factors; having decided that the 202 patent was valid on the standard principles, there was no more role for the IG Farbenindustrie factors to play. Out of an abundance of caution, Zinn J nonetheless went on to hold that in any event, the 202 patent met the IG Farbenindustrie test [106]–[108].