Federal Court affirms principle of claim differentiation in evaluating utility

Justice O'Reilly of the Federal Court has rejected Teva's allegations of invalidity regarding Novartis's patent¹ covering its iron chelator product EXJADE (deferasirox) (2015 FC 770, attached here). Novartis was successful in showing that Teva's allegations of lack of utility (with respect to the compound claims), obviousness, and insufficiency were unjustified.

Utility - The Utility of Compound Claims Differed from the Utility of Use Claims

On the issue of utility, O'Reilly J. applied the principles set out by the FCA in Celebrex² and by Snider J. in Gleevec³, including the principle of claim differentiation, to find that the utility of the novel compound claims (claims 5-37) differed from the utility of the use claims.

O'Reilly J. rejected Teva's argument that the 951 Patent contained an "explicit and overarching promise" that applies across all of the patent's claims, including the claims for novel compounds. He held that the statements in the 951 Patent's disclosure cited by Teva merely provide support for the patent's use claims.

O'Reilly J. recognized that the compound claims made no explicit promise of a specific result, while the use claims contained an explicit promise of use for treatment of an excess of iron in a human or animal body. He thus found that the 951 Patent did not promise that the claimed novel compounds would be valuable in treating iron overload disease in humans.

Applying the above construction, the utility of the novel compounds that were tested, including claim 32 to deferasirox, was held to be "clearly demonstrated". The utility of the claimed compounds that were not specifically tested was held to be soundly predicted.

However, O'Reilly J. held that Teva's utility allegation with respect to the use claims had merit. In this respect, he relied on Teva's allegation that the compounds must be non-toxic, even though toxicity is nowhere discussed in the 951 Patent.

Obviousness - s. 28.3 Does Not Expand the Scope of the Skilled Person's Common General Knowledge

O'Reilly J. had "considerable doubt" that some of the key references that Teva sought to rely on formed part of the relevant prior art and dismissed Teva's argument that s. 28.3 of the Patent Act only requires relevant prior art to be "publicly available" instead of the usual criterion of "discoverable on a reasonably diligent search" (applying Dow Chemical Company v NOVA Chemicals Corporation, 2014 FC 844 at paras 232-236; Eurocopter v Bell Helicopter Textron Canada Limitée, 2012 FC 113 at para 80, aff'd 2013 FCA 219; Eli Lilly and Company v Apotex Inc, 2009 FC 991 at para 532; Takeda Canada Inc v Canada (Minister of Health), 2015 FC 570 at paras 59-60).

Even if the disputed art was considered, O'Reilly J. found that a significant gap existed between the inventive concept and the skilled person's common general knowledge.

Sufficiency - Distinguishing Viagra, the Invention was the Class of Compounds

Teva argued that the true invention was deferasirox, and that the 951 Patent should be invalidated for failing to disclose this fact. O'Reilly J. rejected this allegation and held that the true invention was the novel class of compounds that bind markedly to iron, are soluble in vivo, and induce excretion of the resulting iron complex.

Unlike in Viagra⁴, where the true invention was found to be the one claimed compound that the inventors knew to be useful in treating ED, in this case all thirty individually claimed compounds were found to possess the above properties. O'Reilly J. also found that the patent describes how to make the compounds, thus providing the skilled person with the information necessary to put the invention into practice.

Novartis was represented by Gowlings' Anthony Creber, Jennifer Wilkie, Livia Aumand and Alex Gloor.