SCC Viagra Decision Does Not Create a Duty to Disclose All Test Results

Novartis Pharmaceuticals Canada Inc v Teva Canada Ltd 2015 FC 770 O'Reilly J
            2,255,951 / deferasirox / EXJADE

The background to this decision is given in yesterday’s post. Today’s post deals with Teva’s insufficiency attack. While the SCC’s Viagra 2012 SCC 60 decision was not cited, that decision, and not classic insufficiency, was the basis for the attack. In particular, Teva argued that “the real invention [deferasirox] was buried in claim 32," [56], and that “the patent does not specifically identify the compounds that had been tested in vivo, so a skilled reader would not know which of them would work” [59]. This echos Viagra, in which the SCC held the Pfizer’s Viagra patent invalid for failing to disclose the true invention, essentially on the basis that the patentee had not disclosed that the sildenafil was the only compound which had been tested in humans. The reference to the invention being buried in the claims reflects Viagra because the SCC indicated that if sildenafil had been the only individually claimed compound, that might have constituted sufficient disclosure that it was the true invention. 

The facts in Deferasirox were similar to those in Viagra in that the disclosure did not specifically which compounds had been tested in vivo [59] and numerous compounds were individually claimed. O’Reilly J nonetheless dismissed Teva’s arguments, saying “all of the thirty claimed novel compounds had been demonstrated or soundly predicted to have the stated utility set out in the patent. A skilled person would have had no difficulty making and using any one or more of those compounds based on the information in the patent” [60]. In so holding, O’Reilly J joins prior decisions by Harrington J (here) and Snider J (here) to the effect that Viagra does not impose a general obligation to disclose which compounds were tested. This interpretation of Viagra now seems well-established, at least at the FC level. This is a welcome development. The SCC in Viagra sought to do what it saw as justice, but with a shaky grasp of the facts, which led to a decision which was confusing, and, in my view, doctrinally confused: see “The Duty to Disclose ‘The Invention’: The Wrong Tool for the Job, (2013) 25 IPJ 269. The FC has wisely chosen to interpret Viagra conservatively, rather than as creating a new ground of invalidity.

Emphasis on Good Faith in Teva / Sildenafil Duty to Disclose the Invention

Alcon Canada Inc v Cobalt Pharmaceuticals / moxifloxacin (NOC) 2014 FC 462 Phelan J
            moxifloxacin / 1,340,114 – 2,342,211 – 2,192,418 / VIGAMOX

Friday’s post discussed the promise issue raised by the 114 patent. This post addresses the Teva / Sildenafil 2012 SCC 60 duty to disclose the invention, which was also raised in the context of the 114 patent. In my article “The Duty to Disclose 'The Invention': The Wrong Tool for the Job,” (2013) 25 IPJ 269, I argued that the SCC’s analysis was problematic because it used an objective requirement to disclose the invention under s 27 in addressing what was really an issue of subjective good faith. Phelan J’s moxifloxacin (NOC) decision may indicate a trend of emphasizing the good faith aspect of Teva / Sildenafil.

Cobalt argued that “like the Sildenafil patent, the 114 Patent claims millions of compounds but obscures the identity of the compound that is the subject of this proceeding” [90]. Phelan J held that

[91] Sildenafil is distinguishable from the case at hand in several important respects. Firstly, in that case only sildenafil of the many claimed compounds had been shown to have the promised effect in the treatment of erectile dysfunction. In the case at hand, all of the Example compounds have the promised high antibacterial activity to some degree.

This is indeed an important distinction. As I argued in my “Wrong Tool for the Job” article, the Teva / Sildenafil doctrine will be most problematic when the patentee believes that its invention is a class of compounds with similar properties, so that it does not specifically identify any particular compound, but then it turns out that most of the compounds are not patentable. The patentee will have failed to disclose the true invention – the compound that was in fact patentable – even though it made a good faith disclosure of what it knew at the time. The real test of what Teva / Sildenafil means will come on those facts: if the duty is really to disclose the objective invention, the patent will be invalid, but if the duty is to make good faith disclosure, the patent will be valid. Because, in this case, all the key compounds were useful, this problem did not arise. The true invention really was the class of compounds. This means that moxifloxacin (NOC) does not address this problematic case, which has not yet arisen post-Sildenafil.

With that said, Phelan J strongly emphasized the good faith disclosure aspects of Teva / Sildenafil. After the statement quoted above, he immediately went on to say

More importantly, in Sildenafil there was evidence of bad faith; Pfizer was aware there was only one effective compound and hid it within a larger class in order to mislead” [91, my emphasis].

There are similar references to “improper purpose” [92], “intentionally. . . misleading” [97], “mislead[ing] the public” [98], “bad faith” [100]. In the absence of evidence the patentee withheld information in order to mislead, Phelan J held that the patent was not invalid for inadequate disclosure [98]. I’m not sure that we can really say that this emphasis on good faith disclosure is a trend in the application of Teva / Sildenafil, but it is at the very least consistent with the previous cases.

In my view the emphasis on good faith disclosure is the best interpretation of Teva / Sildenafil, because the alternative approach, which views it as imposing an objective duty to disclose the compound which ultimately turns out to be the true patentable invention, places an impossible burden on the patentee, and eviscerates s 58 of the Act. With that said, the emphasis on good faith disclosure has its own problems, namely that it is unclear how the Teva / Sildenafil duty of good faith disclosure interacts with the wilful misleading provision in s 53, which on its face addresses the same problem. It seems that Teva / Sildenafil has created a new freestanding duty, and it will take some time to ascertain its limits. But that is certainly no criticism of Phelan J’s decision, which takes one step along that path of discovery.

Another Application of the Duty to Disclose the Invention

Pfizer Canada Inc v Apotex Inc / celecoxib (NOC) 2014 FC 314 Harrington J
            2,177,576 / celecoxib / CELEBREX

I blogged yesterday about the promise of the patent in Apotex / celecoxib. This post concerns the second main issue, which is the duty to disclose the invention. There are several points of interest, though none represent major legal developments.

Apotex made three submissions regarding sufficiency of disclosure [43]:

(1) that one individually claimed compounds (Claim 5) was toxic and therefore useless;

(2) Claim 16, to the compounds for use in the prevention of colorectal cancer is unfounded; and

(3) Pfizer failed to disclose that the true invention was celecoxib, (Claim 4) with respect to which Pfizer had already formed the intention to seek regulatory approval.

Taking the second point first, Pfizer effectively conceded, for the purposes of this application, that the compounds were not useful for treating colorectal cancer [46]. But Pfizer has only to establish that one valid claim is infringed in order to obtain an order of prohibition [45], and so Pfizer accordingly argued that the validity of Claim 16 was not determinative of the application, because s 58 provides that claims stand or fall independently. Apotex responded by arguing that the utility of the invention, which is found in the disclosure, is inherent in every claim, and if Claim 16 is invalid, the entire patent falls. Apotex’ argument is set out only summarily by Harrington J, but it is presumably based on on the SCC Teva / Sildenafil 2012 SCC 60, in which a claim to a useful compound was struck down because other claimed compounds lacked utility. I can’t speculate on how exactly Apotex felt that Sildenafil applied to the facts at hand, but in my article The Duty to Disclose “The Invention”: The Wrong Tool for the Job, (2013) 25 IPJ 269, I did argue that the Sildenafil decision eviscerates s 58. Harrington J rejected Apotex’ allegation on this point, holding simply that the submission “is not in accord with s. 58 of the Patent Act and the decision of the Supreme Court in Teva (Sildenafil/Viagra)” [47]. While Harrington J did not elaborate further on the relationship between Sildenafil and s 58, it is clear that he views the two as consistent. While this is contrary to the argument I made in my article, I am nonetheless very pleased by this holding, because I felt that the SCC was wrong to undermine s 58. I said in my article that “I hope that I have misunderstood the court’s holding; I have certainly not found it easy to interpret.” Harrington J’s holding on this point, while not fully reasoned, is a welcome indication that I was indeed wrong in my interpretation of Sildenafil.

The first point, regarding the utility of Claim 5, similarly appears to be relevant only because of its effect on Claim 4, and would also be susceptible to being answered by s 58. But Harrington J addressed the point more directly, holding that

[44] The fact that tests had revealed high doses of the compound in Claim 5 were toxic in rats does not detract from the fact that Claim 5 works as an anti-inflammatory. There was no promise it would receive regulatory approval.

There is a certain tension here with the SCC statement in Tennessee Eastman [1974] SCR 111 that

There is no doubt that when a new substance is claimed as an invention of a "medicine", it has to be shown that it is active and nontoxic in therepeutic doses. Otherwise the patent fails for lack of utility and this is so if a class of substances is claimed some of which are useful as a "medicine", some of which are not.

We might distinguish this on the basis that Tennessee Eastman refers to “therepeutic” [sic] doses, while in this case the toxicity was revealed at “high” doses. However, I think it is more realistic to say that Harrington J’s holding relfected the point made that in Cameron ed Canadian Patent Law Benchbook at §4.8.1.2 that “some care must be exercised in the application of [the Tennessee Eastman] principle].” Apotex Inc / celecoxib should be added to the several cases cited therein as illustrating the conservative interpretation the courts have given to that principle.

I would note also that the view that the claimed compound must be nontoxic in therepeutic doses was obiter in Tennessee Eastman, and it was also obiter in Ciba v Commissioner of Patents [1959] SCR 378, which was relied on in Tennessee Eastman. Ciba in turn cited the decision of Jekins J in Re May & Baker Ltd (1948) 65 RPC 255 (Ch). In May & Baker there was no evidence at all of any utility for the substantial majority of the compounds of the claimed class (p287), which is quite different from a situation, as in this case, where the compounds clearly have a therapeutic effect, and the question is whether side effects would make them not clinically useful in practice. With that said, Jenkins J’s opinion does have statements which might suggest that therapeutic utility in humans, including lack of toxicity, is necessary to support a patent (see esp p 284); but such a suggestion is inconsistent with the holding in Wellcome / AZT 2002 SCC 77 [3] that regulatory approval is not the measure of patentable utility. I note also that the invention at issue in May & Baker was effectively a type of selection invention (p 282-83), so that the claimed compounds had to exhibit some advantage or lack of disadvantage as compared with the prior art compound, which was therapeutically useful, and this may justify the requirement for therapeutic utility on the particular facts.

The third point gets to the heart of the Teva / sildenafil duty to disclose the invention. Apotex argued that Pfizer failed to disclose that the true invention was celecoxib, with respect to which it had already formed the intention to seek regulatory approval [43]. Harrington J readily distinguished Teva / sildenafil from the facts at hand; in the SCC case, the utility of the individually claimed compounds, other than sildenafil itself, had not been established, whereas in this case the utility of all three of the individually claimed compounds was established [59]. Consequently, “[t]he true invention was the class of compounds” [59]. This distinction is, in my view, entirely sound. It is quite similar to, and consistent with, Snider J’s holding in Teva / imatinib 2013 FC 141 (blog). A more difficult question would have arisen had Harrington J come to the opposite conclusion with respect to the compound of Claim 5, so that it could not be said that the true invention was the whole class. In my view, that scenario is where there is a tension between s 58 and Teva / sildenafil. But given Harrington J’s holding that Claim 5 was valid, that tension will have to be resolved on another day.

One point of general importance is that “[t]here was no obligation upon Searle at the time the patent was filed to disclose therein its hope to commercialize Claim 4" [60]. This implies that “the invention” is determined by patentability criteria, and not by business intent. In my view, this holding is entirely consistent with both the Act and Teva / sildenafil.

Finally, Harrington J [50]-[52] also applied the FCA’s direction in Pfizer v. Novopharm / sildenafil (NOC) 2010 FCA 242 [72], to hold that the best mode requirement applies only to machines, notwithstanding Thorson P in Minerals Separation [1947] Ex CR 306, 12 CPR 102, that “the inventor must act uberrima fide and give all information known to him that will enable the invention to be carried out to its best effect as contemplated by him.” While Harrington J was bound to apply the law as set out by the FCA, in a recent article, Best Mode Disclosure in Canadian Patents 25 IPJ 303 (2013), Professor Vaver has argued that on the contrary, the express inclusion of a best mode duty for machines does not impliedly exclude the same duty for all inventions.

Claim to Single Compound Distinguishes Sildenafil

Novartis Pharmaceuticals Canada Inc v Teva Canada Ltd / zoledronate (NOC) 2013 FC 283 Hughes J
            ZOMETA ACLASTA / zoledronate / 1,338,895, 1,338,937

The insufficiency at issue in Sildenafil 2012 SCC 60 is very different from the traditional how-to-make insufficiency, and it is convenient to give them different names. For now, at least, I will refer to “Sildenafil insufficiency” and “classical insufficiency” by analogy with “Biogen insufficiency” (overbreadth) and “classical insufficiency” in UK law.

Sildenafil insufficiency was raised in respect of the ‘937 patent. (For an overview the facts, see yesterday’s post.) While the patent claims zoledronate specifically, zoledronate is not singled out in the disclosure. The disclosure of the ‘937 patent begins by stating that it relates to a class of compounds with the following structure (formula I):


From pages 5-7 the patent lists compounds of formula I to which the invention “relates” or “relates more particularly” or “preferably relates” or “relates firsts and foremost,” but these are all classes of compounds. Zoledronate does fall within the class, but it is not specifically named [69]. The invention is also said to “relate[] specifically to the compounds of formula I and the salts thereof, especially the inner salts and pharmaceutically acceptable salts thereof with bases mentioned in the Examples” [70]. There are about thirty-two compounds specifically named in the twenty examples, and zoledronate appears in two examples. The examples are all examples of how to make the compounds. Note also that this statement says that the invention relates specifically to salts with bases mentioned in the Example, not to compounds mentioned in the examples. So, even though zoledronate is mentioned in the Examples, it is not being singled out as a particularly efficacious compound; it is the salts which are particularly useful. There is no statement in the disclosure of which compounds have been tested for potency, nor is there any evidence discussed by Hughes J as to which compounds had been tested as of the date of the priority application. Zoledronate itself was made and tested in July 1987, which is after the priority application was filed, but before the Canadian application was filed [107].

From this we see that the ‘937 patent is similar to the patent at issue in Sildenafil, in that “No specific attributes or characteristics are ascribed to [the claimed compound] that would set it apart from the other compounds,” and “the patent itself suggests that the entire class of claimed compounds will be effective” [134, quoting Sildenafil [66-67]]. Hughes J nonetheless held that:

the '937 patent, because it claims only one compound, zoledronate, is, on a case-by-case basis, distinguishable from that considered by the Supreme Court in Teva [138].

This distinction does have a sound basis in the passages from Sildenafil [80] quoted by Hughes J at [136]:

The skilled reader knows that, when a patent contains cascading claims, the useful claim will usually be the one at the end concerning an individual compound. . . . However, the public's right to proper disclosure was denied in this case, since the claims ended with two individually claimed compounds, thereby obscuring the true invention.

The SCC acknowledged that even though the disclosure did not specifically identify the compound of particular interest, the claims are part of the specification, and a skilled person would know that the claimed compounds are normally of particular interest. This implies that claiming individual compounds is tantamount to specifically identifying them in the disclosure. The difficulty in Sildenafil was that two compounds were identified, while only one was truly of interest. In this case, only one compound was claimed, so not even a “minor research project” would be needed to identify the compound of interest.

The distinction between one individual compound claim and two, is nonetheless a fine one. This is not to doubt the validity of the distinction. A line must be drawn somewhere, and as just discussed, there is a sound basis for this distinction both functionally and in Sildenafil itself. It does illustrate once again that the Federal Courts appear not to be inclined to use Sildenafil insufficiency aggressively.

On a slightly different point, while the Sildenafil decision formally turned on “what is the invention,” the "key issue in this appeal" was that "patentees cannot be allowed to 'game' the system" [80] (discussed here). It seems to me that the number of claims is not the only distinction to be drawn between this case and Sildenafil. In Sildenafil only one compound had been tested, while in this case it is not clear to me from the decision how many compounds had been tested. Zoledronate had been tested only after the priority application, and it seems unlikely that the priority application had been filed before any compounds at all had been tested. So I would suspect that as of the Canadian filing date, multiple compounds had been tested and shown to have had at least some efficacy. This means the situation may have been more like Imatinib (here), in which several compounds had been tested but none had emerged as the clear favourite. It would have been interesting to have had a more extensive discussion of the "gaming the system" issue from Hughes J, as was carried out by Snider J in her Imatinib decision (discussed here).

Sildenafil Doctrine Not About Data Disclosure

Apotex Inc. v. H. Lundbeck A/S / escitalopram 2013 FC 192 Harrington J
            CIPRALEX / escitalopram / 1,339,452

With the recent Sildenafil 2012 SCC 60 decision, we can expect to see Sildenafil-type insufficiency raised regularly, at least until the bounds of the doctrine are fleshed out. This is second case to deal with the doctrine, and it is consistent with Snider J’s imatinib 2013 FC 141 decision (blogged here) in holding that the Sildenafil doctrine is not about disclosure of data, it is about disclosure of the invention.

The issue in this case was that the specification stated that “results upon administration to human beings have been very gratifying.” This was not true, as the enantiomers had not been tested on humans until after filing [225]. Apotex argued that the patent should therefore be declared void on the basis of s 27(3), which is to say on the basis of the disclosure requirement as interpreted in Sildenafil.

Apotex had raised the same statement in the NOC proceedings, arguing both s 27(3) and s 53 (though of course not relying on Sildenafil). In that case, Harrington J had dealt with it on the basis of s 53, which states that a patent is void “if any material allegation in the petition of the applicant in respect of the patent is untrue.” (He noted in this case that in so doing he had conflated the two provisions.) He had held in the NOC preoceedings that read in context, the statement was not misleading, nor had anyone been misled: 2009 FC 146 [147].

In this case, the point was based on s 27(3), not s 53 [229]. Harrington J again rejected the argument, but on an entirely different basis, tailored to the different provision. He held that the Sildenafil doctrine simply did not apply. In Sildenafil, “the invention was the use of sildenafil for the treatment of ED,” and it was this that had to be disclosed [233, quoting SCC [72]], whereas “In this case, the invention, (+)-Citalopram and how to get there, was properly disclosed” [235]. This strikes me as a correct interpretation of Sildenafil. It is also consistent with Snider J’s imatinib 2013 FC 141 [375] decision, in which she held that failure to disclose test data cannot in itself result in a finding of insufficiency. In imatinib the issue was failure to disclose test data, and in this case it was disclosure of erroneous data, but in either case, the basic principle is that the Sildenafil doctrine is not about disclosure of data, it is about disclosure of the invention.

Finally, I note that Harrington J accepted the view that the SCC in Sildenafil had “declared the patent void, notwithstanding that the appeal was in a PM (NOC) application” [234]. As discussed here, my own view is that the SCC did not hold the patent void in rem.

First Application of the Sildenafil Disclosure Requirement

Teva Canada Ltd v Novartis AG / imatinib 2013 FC 141, Snider J

            GLEEVEC / imatinib mesylate / 2,093,203

Snider J’s Imatinib decision, at [336-387], is the first to apply the disclosure requirement since the SCC released Sildenafil 2012 SCC 60. Snider J has done an admirable job in applying a difficult doctrine, and she has clarified some important points. But the Imatinib decision also illustrates some difficulties that arise from unresolved ambiguities in Sildenafil itself.