Under the doctrine of overbreadth (also referred to as "claims broader than the invention" and "covetous claiming"), a patent is invalid if its claims extend beyond the invention. While seemingly a straightforward idea, there is a lack of clarity for how such an allegation of invalidity is approached by the Court. Two recent Federal Court decisions, Les Laboratories Servier v Apotex (2019 FC 616) ("Laboratories Servier") and Aux Sable Liquid Products LP v JL Energy Transportation (2019 FC 581) ("Aux Sable"), have further muddied the waters in this area.
Allegations of overbreadth have generally been given a limited focus by the Court. Following the rejection of the promise doctrine by the SCC in AstraZeneca v Apotex (2017 SCC 36) ("AstraZeneca"), promise-type arguments were attempted and rejected under the ground of insufficiency. Similar arguments are now being made under the doctrine of overbreadth and, in Laboratories Servier and Aux Sable, have gained traction with the Court.
A promise by any other name
Generally speaking, the promise doctrine required a patentee to establish an elevated level of utility over what was mandated by the Patent Act. The promise doctrine had multiple faults, including that it could require a patentee to have demonstrated or soundly predicted multiple utilities, that it required the patentee to have demonstrated or soundly predicted that each embodiment found across the scope of the claim had utility for each of these promised uses, and that it could require patentees to prove that statements of advantage made in a patent's disclosure were demonstrated or soundly predicted by the filing date. Under the promise doctrine, the failure to meet any of these elevated requirements could result in the entire patent be invalidated. The promise doctrine was a uniquely Canadian patent law doctrine.
The promise doctrine was rejected by the SCC in AstraZeneca. The SCC noted that...
