The Duty of Candour in Canada

Abstract:

In recent years, the question whether there exists in Canada some form of a general duty of “good faith” on patent applicants, and if so the scope of that duty, has been the subject of significant judicial scrutiny. Two past decisions of the Federal Court effectively held that s. 73(1)(a) of the Patent Act (which deems an application abandoned where an applicant fails to reply in good faith to a requisition of a patent examiner) imposes a U.S.-style “duty of candour” on patent applicants such that an issued patent could be rendered invalid on the basis of a finding that the patentee had failed to meet its s. 73(1)(a) obligations during prosecution of the application. However, in the more recent decision of Corlac Inc. v. Weatherford Canada Ltd., the Federal Court of Appeal held that the section applies only to pending applications and cannot be used as a means of attacking the validity of a patent post-grant.