Issues of Patent Drafting in Canadian Patent Law: A Unique Paradigm. By Livia Aumand & John Norman. Gowling WLG (Canada) LLP

Transcription

1 Issues of Patent Drafting in Canadian Patent Law: A Unique Paradigm By Livia Aumand & John Norman Gowling WLG (Canada) LLP In the past years, there has been an evolution in Canadian patent law that impacts the drafting and prosecution of Canadian patent applications. In particular, there are aspects of Canadian patent law that are uniquely Canadian and which present challenges for patentees, patent agents and litigators alike. Those practitioners who are unfamiliar with the nuances of Canadian patent law risk delays in prosecution or, ultimately, rejections by the Canadian Patent Office. Even patents that are allowed are often open to validity attacks when the patent is enforced. However, many potential grounds of invalidity may be avoided or minimized if applications are drafted with a view to the recent jurisprudence, which will be outlined in this paper. In particular, this paper will address three unique, and controversial, areas of Canadian patent law: utility, sufficiency and methods of medical treatment. This paper will also suggest ways to avoid potential issues in both prosecution and in future litigation. Utility a) General As in the U.S., Canadian law requires that an invention be useful in order to be patentable. The requirement is found in the definition of invention in the Canadian Patent Act: invention means any new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter 1 1 Patent Act, RSC 1985, c P-4, s 2 invention (emphasis added). 1

2 This statutory requirement of utility has been held to set a low threshold an invention must have a scintilla of utility to be patentable. 2 In other words, a claimed invention will lack utility only where it is devoid of utility. 3 Historically, inutility was an infrequent ground of attack in patent litigation and was not often raised by the Canadian Patent Office during examination. However, this has changed dramatically with the advent of both the promise doctrine in Canada, as well as an enhanced disclosure requirement in cases where the utility is based upon a sound prediction. b) Promise Doctrine Despite the minimal requirement in the Patent Act for utility, Canadian courts have recently imposed a higher, extra-statutory standard where the patentee promises a higher level of utility. As described by the Federal Court of Appeal in Sanofi-Aventis v Apotex Inc.: An inventor whose invention is described in a patent which would otherwise be valid can nonetheless promise more for his invention than required by the Act so as to render his patent invalid 4 The Intellectual Property Institute of Canada has acknowledged that the promise doctrine now imposes a higher threshold for the utility requirement than other jurisdictions: In Canada, the required utility is normally determined by the promise of the patent. That is, the patent itself is examined to see what utility the inventor has promised, and the patent will be invalid if that utility is not 2 Sanofi-Aventis v Apotex Inc, 2013 FCA 186 [Sanofi Plavix FCA] at para 49; Eli Lilly Canada Inc v Novopharm Limited, 2010 FCA 197 [Lilly Olanzapine FCA] at para Monsanto Company v. Commissioner of Patents, [1979] 2 SCR 1108 at 1117; Apotex Inc v Wellcome Foundation Ltd, 2002 SCC 77 [AZT] at para 62; Apotex Inc v Sanofi- Synthelabo Canada Inc, 2008 SCC 61 at para Sanofi Plavix FCA, supra note 2 at para 54. See also N Siebrasse The False Doctrine of False Promise (2013) 29 CIPR 3 at pp

3 established. This makes utility more difficult to establish in Canada than in the US or Europe. 5 The risk for patent drafters is promising a result that the invention does not deliver. For example, a patent that claims a compound that is useful to treat a disease may well end up being found invalid if the patent is said to promise reduced side-effects as well, and that promise is not accomplished. 6 In fact, there have been several patents that have been invalidated for lack of utility when, in fact, the inventions are useful. 7 The Manual of Patent Office Practice (MOPOP) published by the Canadian Intellectual Property Office (CIPO) indicates that, should a patent contain several promises, it must achieve every one in order to be valid: Although an invention need only have one use in order to be patentable, where several uses are promised the applicant must be in a position to establish each of them. For example, if a composition is promised to be useful as a drug, the applicant must be in a position to show that it is useful in the therapy of at least one disease. If, however, it is promised to be useful as a drug for treating many diseases, the applicant must be in a position to establish its utility 8 Given the consequences of failing to meet a promise, the determination of whether a patent contains a promise and, if so, how to construe that promise is at the heart of many recent Canadian patent law decisions. 9 While there is no clear and consistent approach, certain guidelines have developed in the case law: 5 IPIC (2012) A Comparative Overview of Canadian, US and European Pharmaceutical Patent Systems at p This danger is heightened by the enhanced disclosure requirement of the sound prediction doctrine, discussed herein. 7 See e.g., Eli Lilly Canada Inc v Apotex Inc, 2009 FCA 97 [Raloxifene FCA]; Eli Lilly Canada Inc v Novopharm Ltd, 2011 FCA 220 [Atomoxetine FCA]; Apotex Inc v Pfizer Canada Inc, 2011 FCA 236; Eli Lilly Canada Inc. v. Novopharm Limited, 2011 FC 1288, aff d 2012 FCA 232; AstraZeneca Canada Inc v Apotex Inc, 2014 FC 638, aff d 2015 FCA 158, leave to appeal to SCC granted. See also Siebrasse, The False Doctrine of False Promise supra note 4 at pp Canadian Intellectual Property Office, Manual of Patent Office Practice [MOPOP], Section , available at: 9 Siebrasse The False Doctrine of False Promise, supra note 4 at p 5. 3

4 (a) Canadian courts will only require a patent to meet its promise where there is an explicit promise of a specific result. 10 In other words, a promise must be clear and unambiguous. 11 (b) If a patentee includes a statement as to the goal or objective of an invention, this will likely not to be construed as a promise. 12 (c) Statements made in the claims are presumed to be promises. 13 It is less clear whether statements in the description or disclosure 14 are promises. (d) While a patent may be construed to have made an overarching promise that applies to each claim, it is also possible that different claims have different promises. 15 Further, some claims may have promises (e.g., use claims), while others may only be required to have a scintilla of utility. Despite the above guidance that has developed in the case law, in practice, it is often difficult to predict whether a patent will be said to contain a promise and what that promise will be. In fact, courts have found claims to be invalid where the description and not the claims contain an inferred promise. For example, courts have held that references to a particular disease implies that a compound can be used chronically, as the disease may often require chronic treatment. 16 The combination between the uncertainty and arbitrariness in the law, as well as the fact that the promise doctrine is an extra-statutory requirement that imposes requirements that are beyond both the Patent Act, have resulted in significant litigation on this topic. 10 Lilly Olanzapine FCA, supra note 2 at para Apotex Inc v Pfizer Canada Limited, 2014 FCA 250 [Pfizer Celebrex FCA] at paras 65-67, Pfizer Celebrex FCA, supra note 11 at para 76; Sanofi Plavix FCA, supra note 2 at para Pfizer Celebrex FCA, supra note 11 at para The specification in U.S. parlance. 15 Pfizer Celebrex FCA, supra note 11 at paras See e.g., Atomoxetine FCA, supra note 7 at paras 22-30; Apotex Inc v Pfizer Canada Inc, 2011 FCA 236 at paras

5 The Supreme Court of Canada will likely consider the promise doctrine in its upcoming hearing in AstraZeneca Canada Inc. v. Apotex Inc. 17 This case involves the patent covering the drug esomeprazole (NEXIUM ). While the trial judge in that case found that the claimed invention was novel, unobvious and useful, he ruled that the patent was invalid as it failed to meet the promise that esomeprazole had an improved therapeutic profile. The appellant, AstraZeneca Canada Inc., is asserting that the promise doctrine has no support in the Patent Act and, as such, this unique aspect of Canadian law ought to be abandoned. A decision will likely not be rendered any earlier than Spring Best Canadian Practice In light of the current state of the law, the best practice would be to avoid stating something in the patent with respect to the invention that has not yet been achieved. For example, if the inventors have shown that a new chemical compound grows hair on rats, but has not yet shown the same result on mice, it is best to suggest any use on mice is prospective. It is thus preferable to avoid making strong statements of utility if that utility has not been demonstrated as of the Canadian filing date. For example, if clinical use of a compound is predicted based on in vitro testing models, it is preferable to state that the compound may be useful in clinical situations. Statements that a compound can or will be useful may be more problematic. Another option is to draft different claims covering different uses, 18 which reduces the risk that an overarching promise may be ascribed to all claims. As mentioned above, Canadian courts have held that different claims can have different utilities. Thus, having claims directed to in vitro binding may be helpful in reducing the risk that all claims promise treatment in humans. c) Proving Utility Demonstration vs Sound Prediction Once a determination is made as to whether or what a patent promises, current Canadian law requires that this utility be demonstrated or soundly predicted by the 17 Supreme Court of Canada Case No There are no excess claims fees in Canada. 5

6 Canadian filing date. Since the 2002 decision of the Supreme Court of Canada concerning the drug AZT, a patentee cannot rely on confirmatory post-filing evidence in order to satisfy the utility requirement. 19 As stated by Justice Binnie in this decision: Nor, in my view, is it enough for a patent owner to be able to buttress speculation with post-patent proof, and thereby to turn dross into gold. Utility is an essential part of the definition of an invention (Patent Act, s. 2). A policy of patent first and litigate later unfairly puts the onus of proof on the attackers to prove invalidity, without the patent owner s ever being put in a position to establish validity. Unless the inventor is in a position to establish utility as of the time the patent is applied for, on the basis of either demonstration or sound prediction, the Commissioner by law is required to refuse the patent (Patent Act, s 40). 20 The decision in AZT marked a significant change in the law, as prior to this decision, Canadian courts allowed evidence of utility that was obtained after the Canadian filing date to support an invention s utility. 21 Thus, this requirement is particularly troublesome for those patents who were prosecuted before this decision was rendered. Nevertheless, the law as it stands currently requires the Court (or the Patent Office) to examine the work that was conducted by the inventors prior to the filing date to determine whether the utility was demonstrated or soundly predicted. Utility is held to have been demonstrated where, prior to the filing date, the patentee had shown that the invention in fact had the requisite utility. The available evidence must be strongly suggestive of utility and need not be included in the patent itself. 22 Where utility has not been demonstrated, a patentee may still satisfy the utility requirement where the inventors can show that they had a sound prediction of utility by the Canadian filing date. In the 2002 AZT decision, the Supreme Court held that a sound prediction required three elements: (1) a factual basis, (2) a sound line of reasoning upon which to predict the utility from the factual basis; and (3) disclosure Apotex Inc v Wellcome Foundation Ltd, 2002 SCC 77 [AZT]. 20 AZT, supra note 19 at para AZT, supra note 19 at para AstraZeneca Canada Inc v Mylan Pharmaceuticals ULC, 2011 FC 1023 at para 68, aff d 2011 FCA AZT, supra note 19 at para 70. 6

7 In AZT, the claims at issue covered the use of AZT (a known compound) to treat AIDS in humans. As of the Canadian filing date, no clinical trials in humans had been conducted. However, the patentee had done in vitro human cell line testing (the factual basis for the prediction of use in humans). In addition, the patentee had a theory that AZT worked through what was referred to as the chain terminator effect, which affects the replication of HIV s genetic material. This was the sound line of reasoning the Court stated was required to link the factual basis with the predicted use in humans. 24 With respect to the disclosure requirement, the Court was equivocal. It noted that, since the AZT patent did disclose the testing, as well as the chain terminator effect, there was no reason to discuss this requirement any further. 25 The ambiguous disclosure requirement has caused significant problems for patentees and patent drafters alike since the AZT decision. Many Canadian courts have required that a patentee disclose the experimental test data upon which the prediction of utility is based. 26 Information that would be in the common general knowledge of the person skilled in the art does not have to be disclosed in the patent, even if it is relied upon as part of the factual basis and/or line of reasoning. 27 The Manual of Patent Office Practice describes the disclosure requirement as follows: The requirement for proper disclosure means that the person skilled in the art has to, through the specification alone, be provided with sufficient information to understand the basis of the sound prediction and to practice the entire scope of the claimed invention. Elements of either the factual basis or the sound line of reasoning that form part of the common general knowledge will not, as a general rule, need to be disclosed. Elements that form part of the state of the art could (depending on the specific circumstances) be properly disclosed merely by referring to the document 24 AZT, supra note 19 at para AZT, supra note See e.g., Lilly Raloxifene FCA, supra note 7 at paras 14-15; Lilly Atomoxetine FCA, supra note 7 at paras 47, Eurocopter v Bell Helicopter Textron Canada Limitée, 2013 FCA 219 at paras

8 in which they are contained. Elements known only to the inventors, however, need to be included in the description itself. 28 Like the promise doctrine, the enhanced disclosure requirement is extrastatutory, as there is no statutory provision that obliges patentees to make any disclosure with respect to utility. 29 As the enhanced disclosure requirement entered Canadian law after many patents were filed, there have been several patents that have been held invalid for inutility, even though the inventions may be useful in fact and even though the inventors did, in fact, have a sound prediction of that utility at the time of filing. For example, in Eli Lilly Canada Inc. v. Apotex Inc., the patent at issue claimed the use of the compound raloxifene to treat osteoporosis. 30 At the time the patent application was filed in Canada, the inventors had conducted a study of raloxifene in women. The Court found that the results of this study allowed the inventors to soundly predict that raloxifene would be useful to treat osteoporosis. However, as the results of this study were not included in the patent, the Court found that the utility requirement was not established, based on a failure to meet the disclosure requirement of the sound prediction test. 31 The combination of the promise doctrine, the enhanced disclosure requirement, and the inability to rely on post-filing evidence of utility during prosecution creates a perfect storm of challenges for patentees, patent agents and litigators alike. An otherwise valid patent may be invalidated because a court may find that a patent contains a heightened promise of utility. The greater degree of utility promised, the higher the likelihood that this promised utility was not demonstrated by the filing date. Thus, sound prediction and the enhanced disclosure requirement then become an issue, with potential objections by the patent examiners (or future invalidity attacks). 28 MOPOP, supra note 8 at section c. 29 Teva Canada Ltd v Pfizer Canada Inc, 2012 SCC 60 [Viagra] at para FC 142, aff d Lilly Raloxifene FCA, supra note FC 142 at paras 156, , aff d Lilly Raloxifene FCA, supra note 7. 8

9 Best Canadian Practice Regardless of whether utility is based upon a demonstration or sound prediction, it is prudent to include data supporting the utility of the invention be included in the patent. Even if the utility of certain claims or of some aspects of the invention was demonstrated before the filing date, there may be others that require reliance on a sound prediction. Thus, upon filing an application in Canada, it is prudent to inquire of applicants as to whether they have conducted any additional testing capable of supporting the utility of the invention. Sufficiency a) General In Canada, the role of the specification (which, in Canada, includes both the description and the claims) is to advise the public as to what the invention is and how to put it into practice. As for all other purposes, the person skilled in the art is understood to read the patent in light of the common general knowledge. The sufficiency requirements are outlined at section 27(3) of the Patent Act: 27(3) The specification of an invention must: (a) correctly and fully describe the invention and its operation or use as contemplated by the inventor; (b) set out clearly the various steps in a process, or the method of constructing, making, compounding or using a machine, manufacture or composition of matter, in such full, clear, concise and exact terms as to enable any person skilled in the art or science to which it pertains, or with which it is most closely connected, to make, construct, compound or use it; (c) in the case of a machine, explain the principle of the machine and the best mode in which the inventor has contemplated the application of that principle; and (d) in the case of a process, explain the necessary sequence, if any, of the various steps, so as to distinguish the invention from other inventions. Typically, most invalidity attacks that are made by those challenging a patent are with respect to section 27(3)(a). Attacks on this ground have generally been referred to as 9

10 technical attacks. However, the Supreme Court of Canada recently released its decision in Teva Canada Limited v Pfizer Canada Inc., where the settled law of sufficiency was applied, but in a fairly unique manner. As such, those drafting or prosecuting Canadian patent applications ought to be aware of the potential impacts of this decision. b) Viagra Decision In Teva Canada Limited v Pfizer Canada Inc, 32 the patent at issue related to the drug VIAGRA (sildenafil). The patent claimed the use of a class of compounds to treat erectile dysfunction ( ED ). The description indicated that one of the especially preferred compounds had been shown to work in a clinical trial of patients with ED. However, the identity of this compound (which was sildenafil) was not revealed in the patent. 33 The patent also included claims to the use of varying genera and subgenera to treat ED, as well as two claims to the use of individual compounds to treat ED. One claim covered the use of sildenafil to treat ED. The other claim covered the use of another compound to treat ED. However, there was evidence that this other compound had not been shown to treat ED by the filing date. 34 Before the Supreme Court, Teva argued that the patent was insufficient as the inventors had hid the true invention sildenafil. The Supreme Court agreed and held that the person skilled in the art would not know which compound had been shown to be useful in clinical trials unless they conducted experiments. The Court thus found Teva s allegation of insufficiency to be justified. The decision of the Supreme Court seemed to be influenced by its view that none of the other compounds had been shown to be useful. 35 The Supreme Court did acknowledge that cascading claims were permissible and suggested that, had there been only one individual compound claimed in the narrowest claim, this may have overcome the insufficiency allegation. This was so the person skilled in the art would be aware that this individually-claimed compound was the inventors lead compound. However, since the patent contained two species claims, with no SCC 60 [Viagra]. 33 Viagra, supra note 32 at para Viagra, supra note 32 at paras 5, Viagra, supra note 32 at paras 5,

11 indication as to which compound had been tested in the clinical trials, the Viagra patent was invalid. 36 While the type of argument advanced by Teva in Viagra has been put forward in subsequent cases, it has not been successful to date. In Novartis Pharmaceuticals Canada Inc. v. Teva Canada Limited, 37 the patent at issue claimed a class of compounds and their use to treat excess iron. The patent contained claims to 30 individual compounds, one of which is Novartis commercial product deferasirox (EXJADE ). The Court rejected Teva s allegation that Novartis hid deferasirox, since all of the 30 compounds had been shown to be useful. 38 Best Canadian Practice Thus far, it appears that the Viagra decision has been limited in its application, it is wise that Canadian patent applications do not appear to be hiding important aspects of the invention. If a court feels as though the patentee is trying to game the system by not disclosing the invention, then the entire patent risks being declared invalid and insufficient. As stated by the Supreme Court in Viagra: The disclosure failed to state in clear terms what the invention was. Pfizer gained a benefit from the Act exclusive monopoly rights while withholding disclosure in spite of its disclosure obligations under the Act. As a matter of policy and sound statutory interpretation, patentees cannot be allowed to game the system in this way. 39 Methods of Medical Treatment a) General In Canada, claims to methods of medical treatment are unpatentable. The original basis for this prohibition arose out of an old provision of the Patent Act, which disallowed claims to a medicine itself. 40 As this provision is now repealed, the justification 36 Viagra, supra note 32 at para FC Ibid. at paras Viagra, supra note 32 at para AZT, supra note 19 at para 49; Tennessee Eastman Co. et al. v Commissioner of Patents, [1974] SCR

12 for disallowing such claims is unclear. Some judicial decisions have held that such inventions are not patentable as they are essentially non-economic and unrelated to trade, industry, or commerce. 41 Other decisions express concern that these inventions interfere with a physician s ability to exercise his or her skill and judgment. 42 The Manual of Patent Office Practice gives the following guidance as to when a claim covers a method of medical treatment: To be considered a method of medical treatment, the method should cure, prevent or ameliorate an ailment or pathological condition, or treat a physical abnormality or deformity such as by physiotherapy or surgery. 43 However, methods to treat conditions which are not considered to be pathological such as ageing, pregnancy, baldness and wrinkles do not fall within the prohibition against claiming methods of medical treatment. 44 Further, those claims that do not involve a surgical step or provide a practical therapeutic benefit do not fall within the prohibition. This may permit claims to methods of diagnosing a disease or medical condition or of achieving a cosmetic result. 45 b) Dosage Regimens One type of invention that remains vulnerable to the prohibition against methods of medical treatment are dosage regimens, since the Patent Office is of the view that these are within the purview of a medical professional. 46 The case law on the patentability of claims to dosage regimens is somewhat unclear. However, it can be said that courts generally will not permit a claim that covers a range of dosages (e.g., 5-10 mg) from which a physician could select or a range of dosage 41 Shell Oil Co Canada v Canada (Commissioner of Patents), [1982] 2 SCR 536; AZT, supra note 19 at para Janssen Inc. v. Mylan Pharmaceuticals ULC, 2010 FC 1123 at para MOPOP, supra note 8 at section a. 44 MOPOP, supra note 8 at section a. 45 MOPOP, supra note 8 at section a. 46 MOPOP, supra note 8 at section a. 12

13 frequencies (e.g., every 2-6 days). 47 However, claims that cover a specific dose given at a specific interval (e.g., 1 mg tablet every 5 hours) may be permissible. 48 The following chart gives examples of claims that have been accepted by the courts as patentable subject-matter and those that have been deemed as covering methods of medical treatment. As is readily apparent, there is no hard and fast rule that can be applied in distinguishing the two. Patentable subject-matter Not patentable subject-matter Use of about 1 mg of finasteride once-daily to treat male pattern baldness. (Merck v PMS, 2010 FC 510) Use of range (13-15 mg/kg) of ursodiol once-daily to treat primary biliary cirrhosis (Axcan v PMS, 2006 FC 527) Use of 20 µg ethinylestradiol and 75 µg gestodene (or equivalent amount of one of 3 other gestagens) for contraception. (Bayer v Cobalt, 2013 FC 1061, aff d 2015 FCA 116) Use of ethinylestradiol (at a range of possible dosages) and one of a choice of gestagens (at a range of possible dosages) for contraception. (Bayer v Cobalt, 2013 FC 1061, aff d 2015 FCA 116) Use of about 70 mg alendronate once-weekly to treat osteoporosis. (Merck v Apotex, 2005 FC 755) Use of about 5 mg zoledronic acid about once a year to treat osteoporosis. (Novartis v Cobalt, 2013 FC 985, aff d 2014 FCA 17) Use of galantamine to treat Alzheimer s at a dosage of 8 mg/day 47 See e.g., Axcan v PMS, 2006 FC 527; Bayer v Cobalt, 2013 FC 1061, aff d 2015 FCA See e.g., Merck v PMS, 2010 FC 510; Merck v Apotex, 2005 FC

14 Patentable subject-matter Not patentable subject-matter for 4 weeks and 16 mg/day thereafter. (Janssen v Mylan, 2010 FC 1123) There has been some recent criticism of the courts inconsistent findings with respect to claims to dosage regimens. 49 More broadly, the Federal Court of Appeal raised the issue of whether the prohibition against methods of medical treatment ought to be reconsidered by the Supreme Court of Canada. 50 Best Practice While there is some possibility that Canadian courts may revisit the prohibition against method of medical treatment in the future, based on the law as it stands, it would be best to limit any claims to dosage regimens to a fixed dosage given at a fixed interval. Claims covering ranges ought to be avoided. More broadly, patent drafters ought to avoid language in claims that would suggest a method of medical treatment. Claims drafted as use claims are preferable. Further, the removal of medical aspects of the claim is often necessary. The Canadian Patent Office suggests that: Inclusion of terms such as "cosmetic", "diagnostic" or "non-medical" in a claim may be taken as disclaimers to medical methods provided the description contains adequate support for such terminology and provided the claim can reasonably be understood to be directed to a non-medical method the results of which cannot reasonably be said to produce a practical therapeutic effect N. Siebrasse What Is a Method of Medical Treatment? (29 January 2014), available at: 50 Cobalt Pharmaceuticals Company v. Bayer Inc., 2015 FCA MOPOP, supra note 43 at section a. 14

15 Conclusion As discussed in the within paper, there are distinctive aspects of Canadian patent law evidently present challenges for those prosecuting patents in Canada. While some aspects of this law are in flux, especially those with respect to utility, it is prudent for those practising in Canada to attempt to avoid potential issues in prosecution and enforcement by adapting patent applications to the unique Canadian legal landscape. 15