AstraZeneca has been selling Nexium in Canada for 13 years.\u00a0 It is prescribed to treat ulcers, gastroesophageal reflux disease (GERD) and related diseases. The active ingredient in Nexium is esomeprazole, one of the enantiomers of omeprazole.\u00a0 Omeprazole is also prescribed to treat these same diseases.<\/p>\n
Canadian patent no. 2,139,653<\/a> (the 653 patent) claims esomeprazole with a specified level of optical purity, and its use in the treatment of these diseases.\u00a0 After a 32-day trial (AstraZeneca Canada Inc. et al v. Apotex Inc. et al<\/a>, 2014 FC 638), Justice Rennie found the claimed invention to be new and inventive.\u00a0 However, he held the 653 patent was invalid because it failed to meet the third basic requirement for patentability \u2013 utility.\u00a0 Specifically, the Court found that the inventors could not have soundly predicted one of the utilities promised in the patent at the time of filing the application.<\/p>\n Justice Rennie\u2019s detailed and comprehensive Reasons for Judgment will be of interest to not only litigators engaged in the drug wars in Canada, but also to patent practitioners generally.\u00a0 What follows is a summary of three key issues in that case, but readers of the Court\u2019s Reasons will note that Justice Rennie dealt in detail with several other issues.<\/p>\n <\/p>\n Ascertaining the \u201cPromise\u201d of the Patent<\/b><\/p>\n The Court began its utility analysis by noting that utility is a requirement for an \u201cinvention\u201d under section 2<\/a> of the Patent Act<\/i>.\u00a0 A patent will satisfy the requirement of utility if, from the perspective of the skilled person as of the filing date of the application for the patent, its utility was demonstrated, or in the alternative, its utility was soundly predicted. Prior to engaging in this utility analysis, it is necessary to first ask: \u201cuseful for what?\u201d\u00a0 That is, a preliminary inquiry is to ascertain the \u201cpromise of the patent\u201d, or in other words, determine what the patent says is the utility of the invention.<\/p>\n Justice Rennie recognized that a patent does not need to promise any particular level of utility, in which case the patent will be valid as long as there is a scintilla of utility (citing Eli Lilly Canada Inc v Novopharm Limited,<\/a> 2010 FCA 197). However, where a patent promises a specific result, utility will be measured against that promise so that the question becomes whether the invention does what the patent promises it will do.\u00a0 Identifying the promise of the patent requires a consideration of the patent as a whole construed through the eyes of the skilled person in relation to the science and information available at the time of filing.<\/p>\n Justice Rennie dealt with a number of issues regarding the promised utility of the 653 patent, however, two specific issues are of note: (1) is a property of a compound a promise of utility? and (2) what is the distinction between a promise of utility on the one hand and a goal or advantage on the other hand?\u00a0 With regard to the first issue, the Court found that esomeprazole\u2019s stability against racemization (the single enantiomer does not convert back to the racemate) is a property of the compound \u2013 it is not related to the patent\u2019s utility.\u00a0 Specifically, the Court held that the \u201cpatent in this case is not useful for possessing the chemical property of being stable against racemization; it is useful as a pharmaceutical drug in therapy. Stability against racemization merely enables that use and is not a use in itself\u201d (at paragraph 97).\u00a0 Thus, stability against racemization is a property of esomeprazole that may lead to the ultimate utility of use in treating certain diseases.<\/p>\n As for the distinction between a promise and a goal\/advantage, some recent cases (notably Apotex Inc v Sanofi-Aventis<\/a>, 2013 FCA 186) have held that not all statements of goals or advantages set out in a patent rise to the level of a promise of utility.\u00a0 In particular, a \u201cgoal\u201d is not necessarily a \u201cpromise\u201d, thus it is necessary in some cases to distinguish between the two.\u00a0 In Justice Rennie\u2019s view, \u201cgoals\u201d describe \u201ca hoped-for advantage of the invention\u201d and \u201cmerely relate to potential uses <\/i>for the patent\u201d, whereas \u201cpromises are explicit and define guaranteed<\/i> or anticipated<\/i> results from the patent\u201d (at paragraph 117, emphasis in original).\u00a0 In the context of the 653 patent, the Court held that the patent\u2019s language (\u201cwill give an improved therapeutic profile such as a lower degree of interindividual variation\u201d) clearly refers to a promise of utility. The use of the word \u201cwill\u201d, although prospective, nevertheless conveys \u201ca high threshold of probable<\/i> or certain<\/i> outcomes that will<\/i> occur\u201d (at paragraph 120, emphasis in original). Had the patent used language such as \u201cmay\u201d or \u201ccould\u201d then there would have been a more compelling argument that the statements referred to goals as opposed to promises.<\/p>\n Two final notes of importance about the promised utility of the 653 patent.\u00a0 First, the Court found that the patent made three promises of utility (there has been some debate as to whether a patent can only make one promise), and second, the Court found that the three promises of utility applied to all the claims of the 653 patent (the claims included both compound claims and use claims).<\/p>\n The Disclosure Requirement in Sound Prediction Cases<\/b><\/p>\n Having ascertained the promised utility of the 653 patent, Justice Rennie then turned to the question of whether the inventors had demonstrated the promised utility prior to the filing of the patent application, and if not, whether the promised utility was soundly predicted as of that date.<\/p>\n Determining whether the promised utility was demonstrated is generally straightforward.\u00a0 The question is whether, as of the filing date, there was \u201cevidence that establishes that the embodiment at issue does in fact work in a manner that gives rise to the advantages stated in the patent\u201d (at paragraph 137, citing Eurocopter v Bell Helicopter Textron Canada Lt\u00e9e<\/a>, 2013 FCA 219).\u00a0 In the case of the 653 patent, the promised utility had not been demonstrated. Thus, the issue became whether the promised utility could have been soundly predicted.<\/p>\n It was established by the Supreme Court in the so-called \u201cAZT\u201d case (Apotex Inc v Wellcome Foundation Ltd,<\/a> 2002 SCC 77, [2002] 4 SCR 153) that a three-part test must be satisfied for a patent to be valid based on sound prediction: (1) there must be a factual basis for the prediction, (2) the inventor must have at the date of the patent application an articulable and sound line of reasoning from which the desired result can be inferred from the factual basis, and (3) there must be proper disclosure.<\/p>\n The application of the AZT case has led to a significant debate in Canada as to whether the third step (\u201cproper disclosure\u201d) means that a patent based on sound prediction must satisfy a heightened disclosure requirement in order to be valid.\u00a0 That is, did the Supreme Court require that the patent must disclose both the factual basis and the sound line of reasoning that underlie the prediction of utility?\u00a0 Although the Supreme Court did not have to answer this question in the AZT case, Justice Rennie was not as fortunate.\u00a0 In formulating his answer, he reviewed the law on this point and held that only in the case of a new use patent must the patentee satisfy this heightened disclosure requirement; in the case of all other types of patents, no such requirement exists.\u00a0 His reasoning is as follows.<\/p>\n First, Justice Rennie noted that the AZT case dealt with a new use patent \u2013 the drug AZT was a known drug at the time and the inventors discovered and claimed its use in the treatment of HIV (a new use).\u00a0 Second, certain specific language used in the AZT case suggests that the disclosure requirement applies only to new use patents.\u00a0 Third, obiter dicta<\/i> in the Supreme Court\u2019s recent decision in Teva Canada Ltd v Pfizer Canada Inc<\/a>, 2012 SCC 60 (the Viagra case) rejected the requirement for heightened disclosure and this obiter <\/i>had the effect of overturning prior Federal Court of Appeal decisions where heightened disclosure was required.<\/p>\n Having decided that the factual basis and line of reasoning did not have to be disclosed in the 653 patent, Justice Rennie proceeded to look at all evidence adduced by AstraZeneca relating to the making of the invention, whether disclosed in the patent or not.\u00a0 The Court found, based on the evidence, that two of the three promised utilities had been demonstrated or soundly predicted as of the filing date.\u00a0 However, despite referring to information not disclosed in the 653 patent, Justice Rennie found that the third promised utility was not soundly predictable.\u00a0 As a result, the patent was invalid for failing the utility requirement.\u00a0 Thus, where a patent, properly construed, promises more than one utility, the inventors must have demonstrated and\/or soundly predicted each of the promised utilities, failing which the patent is invalid.<\/p>\n One last point on utility.\u00a0 Justice Rennie began his analysis of the disclosure requirement by saying that the \u201claw on proper disclosure with respect to utility is unsettled\u201d (at paragraph 141).\u00a0 As a result of his decision, the law may now be more \u201cunsettled\u201d than it was previously.\u00a0 Is he correct in his interpretation of the AZT case and of the importance of the obiter<\/i> statements in the Viagra case, or do the holdings in the prior Federal Court of Appeal decisions still apply?\u00a0 As well, how are Examiners in the Patent Office to determine whether the claimed invention was soundly predicted if the factual basis and sound line of reasoning need not be disclosed in the specification?<\/p>\n Ascertaining the Inventive Concept<\/b><\/p>\n A further construction issue faced by Justice Rennie was determining the \u201cinventive concept\u201d.\u00a0 As practitioners are well aware, the Supreme Court in Apotex Inc v Sanofi-Synthelabo Canada Inc<\/a>, 2008 SCC 61, [2008] 3 SCR 265 has mandated a four-part test for assessing obviousness.\u00a0 The second step in the analysis is to \u201c[i]dentify the inventive concept of the claim in question or, if that cannot readily be done, construe it.\u201d<\/p>\n The issue faced by Justice Rennie was how to identify the inventive concept of the 653 patent.\u00a0 He began by noting that the Supreme Court expressly stated that it is the \u201cinventive concept of the claims\u201d that must be identified.\u00a0 Thus, according to Justice Rennie the analysis \u201cbegins with the claims, and only looks to the disclosure when necessary\u201d (at paragraph 267).\u00a0 One of the examples given by the Supreme Court as to when the disclosure may be relied on to determine the inventive concept is in the case of a claim to a bare chemical formula.<\/p>\n Tying the inventive concept to the claims is significant because patentees will generally want to advocate for an inventive concept that includes as many features as possible (thus making it more difficult for a court to find the invention obvious).\u00a0 In some cases, patentees have been successful in convincing the Court that features disclosed in the patent, but not claimed, form part of the inventive concept (see, for example, Allergan Inc. v. Canada (Health)<\/a>, 2014 FC 566 at 25 where a claim to a formulation was characterized as a \u201cbare list of ingredients\u201d).\u00a0 That was precisely what AstraZeneca tried to argue with regard to the 653 patent.\u00a0 Justice Rennie, however, rejected this argument because the claims in issue related to esomeprazole having a specific degree of optical purity.\u00a0 Because of this claimed property, he held there was no need to look to the disclosure, and in particular, no need to import into the inventive concept properties of esomeprazole that were disclosed but not claimed.<\/p>\n