Prior art information – To disclose or not to disclose, that is the question
Unlike in the U.S., Canada does not, per se, require the filing of prior art unless a specific requisition is made by a Canadian examiner. Given this, should an applicant nonetheless voluntarily submit prior art information with the Canadian IPO? The answer is yes. Providing this information voluntarily – and in advance of a first office action – can expedite prosecution, possibly resulting in earlier issuance. Further, there might be legal reasons to do so. Failure to deal with the Canadian IPO by employing the highest duty of candour during prosecution might increase the risk of having subsequently issued patents invalidated by Canadian courts. We discuss some of these cases below.
Certain case law suggests that there is a duty of candour operating in Canada that may be analogous to that found under U.S. law. In Canada, during prosecution, there is an obligation to “reply in good faith to any requisition made by an examiner” otherwise a patent application will be considered abandoned. Historically, it was generally thought that “good faith” functioned as a saving provision – if the applicant or its agent replied incorrectly, but nonetheless “in good faith”, an application would not be considered abandoned. This changed in a Federal Court decision (Searle v. Novopharm ) in which failure to voluntarily provide publically disclosed results of tests that formed part of the prior art resulted in abandonment. Importantly, in arriving at its decision, the court stressed that communications with the Canadian IPO are ex parte, which is a one-sided exchange between the applicant and patent office. As such, the applicant had a high onus to present their position fairly and without bias.
In another decision (Lundbeck v. Ratiopharm ) this obligation was expanded when a patent application was considered abandoned for mischaracterization of prior art. The patent application claimed particular drug combinations and the applicant argued that the prior art as a whole taught away from the claimed combination. The applicant did not mention that a prior art document stated that some combinations were effective while others were not. Again, it was found that there is a duty of candour akin to an ex parte proceeding, and held that the duty was not met. Therefore, the patent application was deemed abandoned.
All of this points to the importance of candour during Canadian prosecution, which could conceivably extend to providing all known relevant prior art information during prosecution. While a more recent decision of Weatherford v. Corlac  held that “the concept of abandonment … operates during the prosecution of the application for a patent” and that “[i]ts operation is extinguished once the patent issues”, on the other hand, it stated that there “is no doubt a duty to act in good faith in dealing with the Patent Office, as recognized by Justice Hughes in G.D. Searle.” Thus, Kirby IP Canada suggests that it is still good prosecution practice to provide prior art information voluntarily through all stages of prosecution, even if it is questionable whether failure to do so results in abandonment of a subsequently issued patent.