On July 18, 2011, the Federal Court of Appeal released its decision in Weatherford Canada Ltd. et al. ats. National-Oilwell Canada Ltd. et al. (A-282-10) upholding the trial judge’s findings of validity and direct infringement of the patent in suit entitled “Sealing Assembly for Rotary Oil Pumps and Method of Using Same,” and the injunction and entitlement to damages that the trial judge had ordered accordingly. Bereskin & Parr LLP acted for Weatherford at trial and on appeal in this case, one that will be of interest to the entire patent profession because it overrules two recent trial level decisions regarding the scope of application of section 73(1)(a) of the Patent Act, and clarifies that there is no general duty of good faith as a condition of the validity of a Canadian patent analogous to the U.S. doctrine of inequitable conduct.
Section 73(1)(a) of the Act provides that an application for a patent shall be deemed to be abandoned if the applicant does not reply in good faith to any requisition made by an examiner in connection with an examination within six months after the requisition is made or within any shorter period established by the Commissioner. In two trial level decisions, G.D. Searle & Co. v. Novopharm Ltd. and Lundbeck Canada Inc. v. Ratiopharm Inc., this section had been construed to permit post-grant attacks on the validity of a patent on the basis that statements made during prosecution were not made in good faith and, therefore, the patent application was deemed to have been abandoned before the patent was granted.
Madam Justice Layden-Stevenson, writing for the Court, overruled these decisions and made it plain that a validity attack on an issued patent on the basis of alleged misrepresentations to the patent office must be dealt with under section 53(1) of the Act (which requires proof of willfulness and materiality as of the date of the grant) since section 73(1)(a) applies to patent applications and not issued patents:
In my view, subsection 53(1) of the Act speaks to misrepresentations in relation to patents, that is, issued patents. Paragraph 73(1)(a) speaks to good faith in the prosecution of the patent application. The provisions are mutually exclusive. This interpretation is consistent with the plain meaning of the provisions, its context within the Act and Canadian jurisprudence. There is no indication that Parliament intended to alter the existing law that establishes a dichotomy between an application for a patent and a patent. 
To be clear, the concept of abandonment in paragraph 73(1)(a) operates during prosecution of the application for a patent. Its operation is extinguished once the patent issues. Post-issuance, the provisions of subsection 53(1) must be utilized with respect to allegations of misrepresentation. To conclude otherwise would result in absurdity. An issued patent would be subject to retroactive scrutiny by the courts in relation to submissions made by an applicant to the Patent Office during prosecution (generally many years prior), judged against unknown criteria. It is for the Commissioner to determine whether an applicant’s response to a requisition from an Examiner is made in good faith, not the court. The courts do not issue patents.