Esomeprazole – Canada

On Jun 30, 2017 in a unanimous decision, the Supreme Court held that the promise doctrine is not the correct approach to determine whether a patent has sufficient utility. As a result, the lower court decisions finding the patent CA 2,139,653 at issue directed to optically pure salts of esomeprazole invalid for want of utility, were set aside [AstraZeneca Canada Inc. v. Apotex Inc., 2017 SCC 36 (on appeal from 2014 FC 638 and 2015 FCA 158)].

Apotex sought to sell a generic version of NEXIUM, applying for a Notice of Compliance to the federal Minister of Health to enable it to do so. AstraZeneca then applied to the Minister of Health to stop the issuance of a Notice of Compliance to Apotex. This application was dismissed by Justice Hughes in 2010, allowing Apotex to launch. AstraZeneca brought an action for patent infringement against Apotex. Apotex counterclaimed for invalidity.

At first instance, Justice Rennie found that the '653 was novel and inventive, but lacked utility.  Although the patent proved to be useful for some purposes, it was invalid because "it promised more than it could provide".  Thus, falling foul of the Promise Doctrine.  The Federal Court of Appeal dismissed AstraZeneca's appeal.  AstraZeneca appealed to the Supreme Court arguing that the Promise Doctrine was unsound. The Supreme Court agreed.

The ruling spells an end to the so-called “Promise Doctrine”. This allowed a patent on a drug to be ruled invalid if a court decided the medication had not lived up to all the promises that a firm had made to be granted the patent in the first place. The Court found that the Doctrine is excessively onerous in two ways: (1) it determines the standard of utility that is required of the patent by reference to the promises expressed in the patent; and (2) where there are multiple expressed promises of utility, it requires that all be fulfilled for a patent to be valid.

The Court stated that utility requires the subject matter of an invention to be useful.  This means that the invention must be capable of an actual use relevant to the subject matter and not devoid of utility.  The Court stated: "A single use related to the nature of the subject-matter is sufficient and utility must be established by either demonstration or sound prediction as of the filing date."

To determine whether a patent discloses an invention with sufficient utility, the courts should adopt a two-stage test:

1      1. Courts must identify the subject-matter of the invention as claimed in the patent

2  2. Courts must ask whether that subject-matter is useful - is it capable of a practical purpose (ie. actual result)

In the case at issue the subject of the patent that must be useful for the purposes of section 2 is the "optically pure salts of the enantiomer of omeprazole". It was accepted at first instance that at the filing date the optically pure salts of the enantiomer of omeprazole would be useful as a proton pump inhibitor to reduce the production of gastric acid.  Use as a proton pump inhibitor is related to the subject matter of the patent, thereby making it useful within the meaning of section 2.  This is sufficient utility to satisfy the requirements of section 2.

The doctrine, which came into force in 2005, has already been used to invalidate almost 30 medical patents.