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Federal Court rejects overarching promise of utility for iron chelation patent

On June 19, 2015 Justice O’Reilly issued reasons in a prohibition application under the PM(NOC) Regulations. Novartis had sough a prohibition Order preventing the Minister of Health from granting Teva a Notice of Compliance for its proposed deferasirox product until the expiry of Canadian Patent No. 2,255,951. The 951 Patent is listed on the Patent Register against Novartis’ EXJADE product, indicated for treating conditions that involve an excess of iron.

Promise of the Patent

Teva alleged that the 951 Patent promises that the claimed compounds, including deferasirox, are useful in the treatment of iron overload in humans. In support of this construction, Teva relied on the following passage from the 951 Patent, which Justice O’Reilly characterized as both the “key phrase” and “infelicitous”:

It has now been found that certain substituted 3,5-diphenyl-1,2,4-triazoles have valuable pharmacological properties when used in the treatment of disorders which cause an excess of metal in the human or animal body or are caused by it, primarily a marked binding of trivalent metal ions, in particular those of iron

Justice O’Reilly held that while the 951 Patent did promise therapeutic utility in humans for the use claims (claims 1 to 4), this promise did not extend to the novel compound claims (claims 5 to 37). Rather, the promised utility of the compound claims was lower – they are useful for their marked iron-binding characteristics in vitro and that they are sufficiently soluble to induce iron excretion in animal models. Finding that Novartis had demonstrated the utility of the tested compounds as of the Canadian filing date, Justice O’Reilly concluded that Teva’s allegation of lack of utility was not justified.

Obviousness

Teva had alleged that if the 951 Patent did not contain an overarching promise of therapeutic utility, then the compound claims should be read as teaching a group of compounds that simply bound iron. Based on this inventive concept, Teva submitted that the compounds of the invention were obvious in light of documents available to the public as of the claim date of the 951 Patent

Justice O’Reilly disagreed with Teva’s inventive concept and held that the inventive concept was a class of compounds with a capacity to bind iron which are soluble in vivo and capable of inducing the excretion of iron. Justice O’Reilly also expressed considerable doubt that all of the prior art cited by Teva would have been found in a reasonable diligent search and rejected Teva’a argument that section 28.3 of the Patent Act no longer requires relevant prior art to be discoverable on a reasonably diligent search.

Even if the art identified by Teva was citable for obviousness, Justice O’Reilly held that there was a significant gap between the inventive concept and the prior art and the inventors of had to apply inventive ingenuity to bridge that gap.

A copy of Justice O’Reilly’s Judgment and Reasons may be found here. On September 17, 2015, Teva commenced an appeal of Justice O’Reilly’s Order.

Teva was represented in this matter by Aitken Klee LLP.