Friday, January 15, 2021

The Limits of Anticipation by Speculation

Teva Canada Innovation v Pharmascience Inc 2020 FC 1158 Kane J

2,702,437 / 2,760,802 / glatiramer acetate / Copaxone / Glatect / NOC

The patents at issue in this case relate to the use of glatiramer acetate for the treatment of multiple sclerosis [MS]. Glatiramer acetate was known to be effective in treating MS, with a standard dose of 20mg daily, administered by subcutaneous injection. The 437 patent claims the early use of glatiramer acetate for the purpose of delaying the development of MS, while the 802 patent claims a dosing regime of 40mg three times a week. The decision turned largely on the facts (to the tune of 936 paragraphs!), but a few points of interest were raised, particularly in the discussion of the 437 patent, which Kane J held to be novel, but invalid for obviousness. Kane J's holding that the 802 patent was not invalid for obviousness or lack of utility, and that it would be infringed by Pharmascience's 40mg product, turned on the facts.

MS is a disease of the central nervous system in which the patient’s own immune system attacks the myelin of the CNS. The early course of the disease is characterized by intermittent attacks, which include episodes of numbness, muscle weakness and spasticity, etc [73]. The disease also gives rise to lesions on the CNS resulting from destruction of the myelin sheath [71]. Patients who present with a single clinical attack having features typical of MS were considered to have a “clinically isolated syndrome” (CIS) [77]. CIS patients are at elevated risk for MS itself (also referred to as “clinically definite MS” or CDMS), but not all CIS is caused by MS, so CIS patients are not considered to actually have MS.

The inventive concept of the 437 patent is that glatiramer acetate could be used to delay the onset of clinically definite MS in CIS patents at risk of developing MS [569]. Accordingly, Claim 1 was to glatiramer acetate “for use in delaying the onset of clinically definite multiple sclerosis,” in a patient who presents with at least one lesion “suggestive of multiple sclerosis” and who is “at risk of developing” clinically definite MS, and “prior to development of clinically definite multiple sclerosis” [251].

The claim construction debate turned on the fact that around the time of filing, in 2007, the criteria for diagnosing MS were changing. The older Poser criteria relied on clinical signs, ie two clinical attacks. The new McDonald criteria were developed to take advantage of the use of MRI for diagnosis using direct detection of lesions characteristic of MS with less reliance on clinical signs. The result is that some patients who would not have been diagnosed as actually having MS using the Poser criteria, would be diagnosed as having it using the McDonald criteria. The 437 patent was apparently developed with the Poser criteria in mind and there was a long and involved argument as to whether the patients with MS according to the McDonald criteria would be included in the claim; if so, the claim would not be novel, as the use of glatiramer acetate for treating MS was known [305].

I must admit that I was having trouble following the argument and its significance, and I was relieved when Kane J stated that “In my view, far too much time and effort was devoted to debating the meaning of the terms, the evolving diagnostic criteria and the scope of the patients covered by the claims” [306] . All the experts construed the claims in accordance with their plain language, which did not specifically refer to either set of criteria by name, and “the claims mean what they say” [307]. Kane J held that on a plain reading of the claims they were directed to a patient who did not already have a confirmed diagnosis of MS, and so did not include patients who already met the McDonald criteria [329]. This reading seems eminently sensible to me. The result of this claim construction holding was to negate both anticipation based on the Pinchasi 2007 prior art [454] as well as the Gillette defence [396], [403].

In light of this conclusion on claim construction, the more interesting anticipation argument was based on the Karussis 2006 prior art. This was a report of an International Working Group for Treatment Optimization in MS [458]. The report suggested the use of therapies approved for treatment of MS itself, which prominently includes glatiramer acetate, as a possible treatment for patients at risk of developing MS (ie, those with CIS), but acknowledged that this was an inference and was not based on evidence [464], [465]. So, the Working Group concluded that “as [other therapies] and glatiramer acetate have been shown to be effective in [the most common form of diagnosed MS], and a patient with a CIS is highly likely to progress to MS, it is reasonable to propose early treatment with [therapies approved for treatment of MS] at the doses approved for MS, even though there is not yet evidence to support this approach” [465]. The question is whether this and similar statements anticipated the claims of the 437 patent.

This raises the issue of what I have called “anticipation by speculation,” as raised in Hospira 2020 FCA 30 and Biogen v Taro 2020 FC 621, which held that similarly speculative statements were anticipatory. As discussed here and here, my view is that Hospira and Biogen v Taro stretched anticipation to the very limit, and perhaps beyond. In this case, Kane J held that Karussis 2006 was not anticipatory. This is not to say that Kane J’s holding is necessarily inconsistent with Hospira and Biogen v Taro, which Kane J considered and distinguished on the facts: [479]–[482]. I won’t go through all the particular grounds, though I will say that the distinctions she draw struck me as generally reasonable; as always in borderline cases, some of the distinctions to be drawn will necessarily be fine and turn on the particular facts. The broader point is that Kane J’s holding illustrates that anticipation by speculation can only be pushed so far and the line is somewhere in this general vicinity.

One general observation made by Kane J is worth pointing out (my emphasis):

[484] In my view, if Karussis 2006 is anticipatory art, what would prevent a group of experts in any field from having discussions and speculating on the positive outcome of a clinical trial in progress, developed and implemented by others, in order to later argue that their speculation that the trial in progress would be successful anticipated the claims of a patent that are based on such clinical trials. This approach seems to be inconsistent with the objectives of the experimental use exemption established in the common law.

[485] As noted by Teva, the law recognizes that there is no disclosure for the purposes of anticipation where a prior use is experimental. If a patent cannot be anticipated by its own clinical study, in my view, it cannot be anticipated by the speculative recommendations of a group of experts who discuss the state of MS treatment, note the lack of evidence, and note that trials are underway.

Kane J then went on to hold that Karussis 2006 did not in any event satisfy the enablement branch of anticipation: [486]–[493].

All that was for nought, so far as Allergan is concerned, as Kane J then went on to find the 437 patent invalid for obviousness on an obvious-to-try analysis. This is likely to be common in cases where a clear suggestion to try the invention can be found in the prior art, especially since the holding in Hospira 2020 FCA 30 that the state of the art for purposes of an obviousness attack includes all prior art. Exactly where we draw the line on anticipation is now less important, because if an obscure piece of prior art does not quite reach the level of anticipation, it can still be used as the basis for an obviousness attack. With that said, it does not appear that the Hospira rule made any difference in this case; while Karussis 2006 was not common general knowledge, it reflected several studies that were [573].

I’ll finish with two quick points on obviousness.

First, Kane J clearly stated that the mere fact that it is not self-evident that the invention will work, before any experiments are undertaken, does not mean that it is not obvious.

[593] Dr. Selchen’s opinion that the invention was not self-evident appears to conflate the obvious to try test with the factor or consideration that informs the test, i.e., whether it was self-evident that it would work, in the sense of being effective for CIS patients to delay the onset of MS and achieve the other claimed benefits.

I entirely agreed with Kane J on this, but it is a point that continues to pop up and cause confusion, as it did for Dr Selchen in this case.

Second, Kane J recognized and applied the “golden bonus” rule, usually traced back to Hallen v Brabantia [1991] RPC 195, 216 (CA), which says that if an invention is obvious for one reason, it does not become non-obvious merely because it has some non-obvious benefits (the "golden bonus"):

[594] Teva’s submission – that the therapeutic benefits or outcomes of the ‘437 Patent were not obvious or expected – does not diminish that the invention was obvious to try. In Janssen [2015 FC 184] at para 100 [see here], the Court explained, that “if a patentee obtains a workable formulation, the later discovery of one of its inherent characteristics does not add anything inventive to what had already been discovered: see Alcon Canada Inc. v Apotex Inc., 2012 FC 410 at para 45, [2012] FCJ No 1707 (QL).” In the present circumstances, once the POSITA pursued the use of glatiramer acetate for CIS patients, the claimed benefits would follow.

As Kane J notes, this is not an entirely new development in Canadian law, but it is nonetheless welcome to see the point expressly recognized and affirmed. I believe that this is the first time that the phrase “golden bonus” has actually been used in a Canadian case [510].

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