The FCA has released its reasons in the appeal of Justice Rennie’s Esomeprazole decision.1 In Esomeprazole, Rennie J. found Astrazeneca’s patent to be invalid for failing to demonstrate, or soundly predict, the promised utility. Rennie J. also undertook a thorough analysis of the jurisprudence and arrived at the conclusion that the factual basis and the line of reasoning underlying a sound prediction need not be disclosed, except possibly in the case of patents that claim a new use for an old compound. The FCA dismissed Astrazeneca’s appeal.

Issues Relating to Construction of the Promise

The FCA decision dealt primarily with issues relating to the promise. The patent at issue had both compound and use claims, not unlike the patent at issue in the Celebrex decision. On appeal, Astrazeneca argued that the claims must be assessed on a claim by claim basis in assessing utility. Namely, Astrazeneca’s position on appeal was that a lower level of utility should apply to the compound claims. Astrazeneca further argued that the trial judge erred in accepting Apotex’s position that the promises were overarching (i.e. applying to each claim). Finally, Astrazeneca argued that the promise should not have been inconsistent with the inventive concept as determined, attempting to apply the doctrine that one construction should be given for all purposes.

The FCA agreed with Astrazeneca that “it is well settled law that inutility must be assessed on a claim by claim basis”,2 and that promises are not necessarily overarching (i.e. they can apply to only a subset of the claims).3 However, the FCA held that the trial judge was entitled to rely on the lis as framed between the parties, and that the lis only contemplated an overarching promise.4 Therefore, while Astrazeneca’s legal position that utility is to be assessed on a claim by claim basis was correct, the failure to frame the issue of promise construction before Rennie J. as a claim by claim issue was fatal on appeal.

The FCA also found that it was not an error of law for the claimed utility to differ from the inventive concept.5

The (non)-Requirement for Disclosure in Cases of Sound Prediction

At trial, Rennie J. discussed the disparate requirements of utility and sufficiency in considering whether there was a need in Canadian patent law to disclose the factual basis and line of reasoning in cases of sound prediction. In short, he looked at whether a “heightened disclosure requirement” for sound prediction cases was mandated by the Patent Act, and at the impact of the Supreme Court of Canada’s AZT decision on this issue. After analyzing the jurisprudence and the Patent Act, Rennie J. found that a disclosure of utility can only be required where the invention (required to be disclosed under section 27(3)(a)) is the patent’s utility, such as inAZT.6 As the instant patent claimed novel compounds, Rennie J. found that no requirement existed for AstraZeneca to disclose the studies it relies upon for a sound prediction in the patent.7

This aspect of Rennie J.’s decision was not discussed in the present appeal.