Crystalline Form Not Obvious to Try

Apotex Inc v Pfizer Canada Inc 2019 FCA 16 Boivin JA: Webb, de Montigny JJA aff’g 2017 FC 774 Brown J
Teva Canada Ltd v Pfizer Canada Inc 2019 FCA 15 Boivin JA: Webb, de Montigny JJA aff’g 2017 FC 777 Brown J

2,436,668 / desvenlafaxine (ODV) / PRISTIQ / NOC

In ODV the FCA has affirmed Brown J’s finding that Claims 8 and 9 of the ‘668 patent, to Form I ODV succinate (a particular crystal form of a particular salt of the compound ODV), were not obvious. The decision turns on the obvious-to-try analysis: see here for a review of the facts. The FCA decision does not apply new law, but it is another helpful discussion of the obvious-to-try analysis applied to the particular facts. It is useful to contrast this case, in which the crystalline form was found not to be obvious on an obvious-to-try analysis, with Dasatinib 2017 FCA 190 aff’g 2017 FC 296, holding the claims at issue to be obvious-to-try: see here for a discussion. These are companion cases, and the reasons are largely the same. This discussion will refer primarily to the Apotex decisions, simply because it is the one I happened to read first.

As the FCA discussed in Atazanavir 2017 FCA 76 (see here), as well as in Ciba v SNF 2017 FCA 225 (see here), the role of the inventive concept in an obviousness analysis has been problematic. In this case, it was uncontested that the inventive concept of the relevant claims is Form I ODV succinate. Apotex’s main argument was that “the Federal Court Judge erred when he made reference to the properties of ODV succinate – and specifically Form I – in his reasons as they are not part of the inventive concept” [37]. This is an important point. An obvious to try analysis is likely to be appropriate “where advances are often won by experimentation” (Sanofi [68]). In such a case, the detailed properties of the invention normally cannot be predicted in advance. If the detailed properties are part of the inventive concept, then the claimed invention would never be obvious, even though it was obvious to try and succeeded without the need for inventive ingenuity, as, for example, in Dasatinib. The FCA acknowledged this concern:

[38] I am mindful that our Court cautioned in Atazanavir to not implicitly adopt a definition of the inventive concept that focuses on properties if the properties are not part of the inventive concept (Atazanavir at para. 74).

In the Teva appeal, the Court noted that there was no dispute between the parties that the inventive concept does not include properties [32]. (This is not to say that the properties can never be part of the inventive concept, as the Court indicated in [38].)

Apotex’s complaint did have some basis in Brown J's reasons; in places, he did discuss the properties of ODV in a way that could be taken to imply that it would have been necessary to be able to predict its properties from the prior art: see eg the passages quoted at [38]. However, when read as a whole:

the Federal Court Judge did not find non-obviousness on the basis that the properties were not predictable in the manner seemingly suggested by Apotex. Indeed, although the Federal Court Judge discusses properties in various parts of his reasons, his conclusion that Form I ODV succinate is not obvious does not rest solely on the unpredictability of the properties of a salt form. Rather, the Federal Court Judge relied on evidence that demonstrated that a skilled person could not have known or predicted that the Form I ODV succinate – i.e., the crystal form itself – could be made or even existed:

So, Brown J found that “the number of experiments required to move from the acceptable pharmaceutical salts to the Form I ODV succinate was extremely large, as Dr. Myerson deposes at para 102 of his affidavit, and in the nature of a research program, not routine experimentation” [FC 230] quoted at [38]. So, on the facts, actually making the crystal form required inventive ingenuity, quite aside from whether the properties are part of the inventive concept, or could have been predicted.

The FCA also affirmed that the jurisprudence “does not establish any “hard and fast rules” on obviousness when it comes to evaluating whether or not a salt screen or any other form of experimentation is obvious or not” [42]. Whether salt forms, polymorphs or crystalline forms are obvious will turn on the facts of the case.