Supreme Court of Canada to consider law of utility in Esomeprazole appeal

The Supreme Court of Canada has again acknowledged the need to consider the law of utility in Canada by granting Astrazeneca leave to appeal in Esomeprazole.¹ At issue will be the validity of Canadian Patent 2,139,653 ("653 Patent”) covering Astrazeneca’s NEXIUM® product, which has previously been declared invalid by Rennie J., as confirmed by the Federal Court of Appeal (“FCA”).²

The Esomeprazole appeal appears to centre around two primary issues: (1) is the so-called “promise doctrine” properly part of Canada’s wholly statutory patent law? (2) what is the proper standard of utility under Canada’s Patent Act? A third issue that may arise is whether any disclosure requirement can be incorporated into the utility doctrine of sound prediction.

The Trial Decision

The 653 Patent was declared invalid at trial for failing to demonstrate or soundly predict the promised utility. Apotex argued at trial that the 653 Patent contained multiple promises that applied to each claim of the 653 Patent. The Trial Judge (Rennie J.) agreed, finding that the 653 Patent “supported” three promises. While two of these promises (use as a proton pump inhibitor and stability against racemization) were found to be met as of the filing date, the 653 Patent was declared invalid because the third promise, an improved therapeutic profile, was not demonstrated or soundly predicted.³

Rennie J. also provided a detailed explanation of why the doctrine of sound prediction does not require disclosure of the factual basis or line of reasoning. In so doing, Rennie J. distinguished the Patent Act’s distinct requirements under section 2 (utility) from section 27(3) (sufficiency). Rennie J. drew support from the Supreme Court’s Viagra decision in this analysis.⁴

The Federal Court of Appeal Decision

The FCA affirmed Rennie J.’s reasons, commenting that: “the Federal Court directed itself to the correct legal tests applicable to claims construction, inventive concept and utility”.⁵ The FCA also addressed the notion that a given claim’s utility need not be coterminous with its inventive concept, holding that there was no support for this proposition.⁶  The FCA found that, based on the arguments before him, Rennie J. made no legal error in his construction of the promise and held that there was no palpable and overriding error in his appreciation of the evidence.

What to Expect

The Supreme Court previously recognized the national importance of clarifying the law of utility in Canada by granting leave in the case of Plavix.⁷ The appeal in Plavix focused on whether the “promise doctrine” is properly maintainable under Canadian law and on whether there was a heightened disclosure obligation where utility was based upon a sound prediction. However, Apotex discontinued its appeal the day before it was scheduled to be heard, opening the door for the present appeal.⁸

Thus, it is expected that the Court will address the promise doctrine. Sub-issues may include whether there is any statutory basis on which to base the promise doctrine and whether the promise doctrine provides the predictability and fairness expected in a national patent system.

Other issues that may be commented on include whether a claim’s utility need be coterminous with its inventive concept, as well as Rennie J.’s analysis regarding the interplay between the Patent Act’s section 27(3) disclosure requirement and its section 2 utility requirement.

The case will be closely watched. It will likely be heard in late 2016 or early 2017.

¹ SCC Case Number 36654, coram of McLachlin CJ, Moldaver and Gascon JJ

² Esomeprazole Trial: 2014 FC 638, discussed here.

Esomeprazole Appeal: 2015 FCA 158 discussed here.

³ Esomeprazole Trial at paras 133-195

⁴ 2008 SCC 60 at paras 38-40

⁵ Esomeprazole Appeal at para 11

⁶ Esomeprazole Appeal at para 12

⁷ SCC Case Number 35562

⁸ SCC Case Number 35882