Canadian Federal Court of Appeal Rejects “Lack of Good Faith” as Grounds for Patent Invalidation

A recent Federal Court of Appeal (FCA) decision in the case of Corlac Inc. et al. v. Weatherford Canada Limited et al. has clarified Canada’s position on “lack of good faith” as suitable grounds for patent invalidation.

Originally, Weatherford Canada Ltd., licensee of Canadian Patent No. 2,095,937 (the ‘937 patent), brought an infringement action against Corlac Inc.  The Federal Court held that the  ‘937 patent was valid and infringed.

On appeal, Corlac argued that the patent was invalid due to technical non-compliance with Section 73 of the Patent Act.  Corlac cited section 73 (1) (a), which requires the applicant to “reply in good faith to any requisition made by an examiner”.  Corlac suggested that the applicant failed to meet the duty of good faith and thus, that the application should have been abandoned.

The FCA however held that the operation of s. 73(1)(a) of the Patent Act is extinguished once the patent issues.  The Court reasoned that the concept of abandonment under s. 73(1)(a) operates during the prosecution of the application only.  The FCA further stated that relying on s. 73(1)(a) post-issuance to challenge the validity of a patent would allow an issued patent to be subject to retroactive scrutiny by the courts in relation to submissions made by a patent applicant to the Patent Office during prosecution.  The Court explained that: “[i]t is for the Commissioner of Patents and not the courts to determine if those submissions were made in good faithin response to a requisition from an examiner”.

The FCA has now established its position on this point by concluding its analysis with the following reference to these cases:

“To the extent that the Federal Court decisions in G.D. Searle and Lundbeck can be interpreted as standing for the proposition that paragraph 73(1)(a) can be relied upon for the purpose of attacking the validity of a patent, they should not be followed.”


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