Supreme Court

Intellectual Property


Validity of patent

Promise doctrine not correct approach to determining patent’s utility

In infringement/impeachment action, plaintiffs’ patent relating to its drug with compound esomeprazole, used as proton pump inhibitor (PPI) to treat various maladies, was declared invalid for inutility. Plaintiffs’ appeal was dismissed. Plaintiff appealed. Appeal allowed. Promise doctrine applied by trial judge and appeal court was not correct approach to determine whether patent had sufficient utility. Doctrine was unsound and excessively onerous, conflating s. 2 of Patent Act that defined what qualified as invention to obtain protection of patent with disclosure requirements of s. 27(3) of Act. Promise doctrine’s approach to multiple promised uses, requiring all of them to be demonstrated or soundly predicted by filing date even though any single use was sufficient to make invention useful for purposes of s. 2 of Act, had punitive and potentially unfair effect. Approach risked depriving otherwise useful invention of patent protection because not every promised use was sufficiently demonstrated or soundly predicted, which would discourage patentees from making full disclosure contrary to purpose of s. 27(3) of Act. Correct approach was to identify subject-matter of invention and then ask whether it was useful in that it was capable of practical purpose, rather than being speculative or fanciful. Trial judge accepted that drug compound’s use as PPI to reduce production of gastric acid was soundly predicted by relevant date. Use as PPI was appropriately related to patent’s subject matter of compound. Patent had sufficient utility to satisfy requirement of s. 2 of Act and so was not invalid for inutility.

AstraZeneca Canada Inc. v. Apotex Inc. (2017), 2017 CarswellNat 2988, 2017 CarswellNat 2989, 2017 SCC 36, 2017 CSC 36, McLachlin C.J.C., Abella J., Moldaver J., Karakatsanis J., Wagner J., Gascon J., Côté J., Brown J., and Rowe J. (S.C.C.); reversed (2015), 2015 CarswellNat 12189, 2015 CarswellNat 2431, 2015 FCA 158, 2015 CAF 158, Eleanor R. Dawson J.A., C. Michael Ryer J.A., and Wyman W. Webb J.A. (F.C.A.).


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