Another Restrained Construction of the Promise post-Plavix

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

Phelan J’s Cobalt / moxifloxacin (NOC) decision doesn’t make new law, but it does confirm two significant emerging trends. The first, which is the subject of this post, is the trend to construing the promise of the patent modestly, following the FCA decision in Plavix 2013 FCA 186 (blog) (leave to appeal to SCC granted). The second is that the duty to disclose the invention established by the SCC in Teva / Sildenafil 2012 SCC 60, is generally being construed as a requirement of subjective good faith disclosure.

Cobalt sought to market a generic version of VIGAMOX, which is an antibacterial eye drop containing moxifloxacin [1]-[2]. The promise and disclosure issues were raised in respect of the 114 patent, which has compound claims to all four stereoisomers of moxifloxacin (Claim 8) and to the two “cis” isomers (Claim 13) [42]. Infringement was conceded and the main attack on validity turned on the promise of the patent [53].

Cobalt’s main submissions were that the patent promised low toxicity and antibacterial activity against a broad spectrum of bacteria [54], based on statements in the description that

For example, local and/or systemic diseases caused by the following pathogens or by mixtures of the following pathogens can be treated and/or prevented: [long list of pathogens] [60].

The compounds according to the invention, while having a low toxicity, exhibit a broad antibacterial spectrum against Gram-positive and Gram-negative germs. [63]

The affirmative language, “can be treated,” “having” low toxicity, might well have lent itself to being interpreted as a promise pre-Plavix, but Phelan J interpreted both modestly, replying on the expert evidence and the text. He held that “For example” indicated that the first passage did not indicate effectiveness against all listed diseases, but rather some degree of activity against some of the diseases [60]. He found the toxicity passage to be not sufficiently explicit [64]. This is formally consistent with the pre-Plavix cases, in that the promise is construed on the basis of the text and expert evidence, but his analysis and conclusions clearly show the impact of the FCA’s direction in Plavix that any promise must be explicit, and that it should not be assumed that every patent has a promise. In this respect, Phelan J’s decision is consistent with Harrington J’s recent decision in celecoxib (NOC) 2014 FC 314, as discussed here.

Phelan J also made two statements of general interest. First:

[65] The notion of toxicity relates to safety and potential commercial success; not patentability. As held in Apotex Inc v Wellcome Foundation Ltd, 2002 SCC 77, [2002] 4 SCR 153 [AZT], proof of lack of toxicity at this stage of analysis is not necessary to show utility.

This follows (without citing), statements to the same effect made by Hughes J, 2011 FC 547 [247], 2011 FC 239 [116]. As discussed in my post on Harrington J’s celecoxib (NOC) decision, this is in tension with some prior SCC authority, but it now seems to be established, based on Wellcome / AZT, that notwithstanding the prior cases, proof of lack of toxicity is not necessary to demonstrate utility. In my view, this is entirely sound, both in principle and on the basis of Wellcome / AZT. Toxicity is a relative term. Many cancer drugs are toxic in any ordinary sense of the term – indeed, that is how they work – and yet they are approved for treatment. A drug might be too toxic for one indication, and yet approved for another. With the rise of personalized medicine, we may find drugs that are toxic to one person and therapeutic to another. Toxicity is best left to the regulatory process, which is the implication of Wellcome / AZT that is made express in the subsequent FC cases.

The second interesting statement is this:

[68] In light of the finding in Consolboard Inc v MacMillan Bloedel (Saskatchewan) Ltd, [1981] 1 SCR 504, and more recently in Plavix that there is no requirement to make a promise, but if made the patentee is held to it, there is no evidence of advantage to making a promise. To read in a promise in these circumstances would be to inject meaning for the purpose of defeating the 114 Patent.

This makes the very good point that making an explicit promise is never in the patentee’s interest, so perhaps it should be presumed that the patentee did not intend to make any promise. 

Phelan J concluded that “To the extent the patent promises anything, it is limited to a promise that the class as a whole will have in vitro activity against a broad spectrum of bacteria. Accordingly, based on Plavix the question becomes whether there is a scintilla of utility” [71]. The first sentence indicates that there was a promise, albeit a modest one, while the second sentence indicates that there was no promise at all, a result which is theoretically possible in Canadian law, but which has rarely been observed since the promise doctrine emerged. In any event, it was conceded that utility had not been demonstrated, because moxifloxacin had not been synthesized or tested as of the filing date, but on the facts Phelan J held that its utility was soundly predicted based on its similarity with compounds which had been tested and disclosed. The question of whether the factual basis for sound prediction must be disclosed in the specification did not arise, because the factual basis that was disclosed was a sufficient basis for a sound prediction.