Supreme Court Curtails Inutility Challenges With Its AstraZeneca Decision

In Astra-Zeneca Canada Inc. v. Apotex Inc., 2017 SCC 36, the Supreme Court has significantly curtailed the ability to challenge a patent monopoly on the basis of an unsubstantiated promise in the patent application that the claimed subject matter of the patent will provide a particular utility [ie. the "optically pure" substance will have an "improved therapeutic profile"]. This type of challenge was known as the "promise doctrine". The doctrine called for an analysis of the specification and its' claims independent of the purposive construction of the claims for the purposes of determining novelty and obviousness. The Supreme Court has now held the "promise doctrine" to be an incorrect approach for determining whether a patent is invalid for want of utility.

In the Astra-Zeneca case, the trial judge had held the "improved therapeutic profile" was not essential to the claims to the "optically pure" substance. Therefore, according to the Supreme Court, it was an error to invalidate the claims on...