In the Federal Court's decision in The Dow Chemical Company et al v NOVA Chemicals Corporation, 2014 FC 844 ("Dow v NOVA"), in the face of a multi-faceted validity attack, Dow's Canadian Patent 2,160,705 (the "705 Patent") was found valid and infringed by NOVA.

Justice O'Keefe's detailed reasons set out the law relating to various patent principles including patent construction, infringement, utility, claims broader, anticipation, obviousness, and double patenting. As set out and applied by Justice O'Keefe, these principles will have general application to all patent infringement and validity cases. This article will discuss some particular points of interest.

Infringement: Shifting the burden to the defendant

The 705 Patent claims novel ethylene polymer compositions, which are used in thin film products for the packaging industry (e.g., merchandise bags and grocery bags).

To establish infringement, the plaintiff Dow's expert reproduced polymers that were intended to represent NOVA's SURPASS polymers. These polymers were tested and found to have a strain hardening coefficient ("SHC") within the range claimed in the 705 Patent.

NOVA did not perform any testing and instead attacked the testing done by Dow's expert. Justice O'Keefe, citing Eli Lilly and Co v Apotex Inc, 2009 FC 991 ("Cefaclor"), noted that the burden for proving non-infringement may shift to the defendant where the defendant fails to bring forward evidence within its knowledge or ability to produce. NOVA's challenges to Dow's testing failed and its absence of testing evidence proved to be detrimental to its non-infringement argument.

Justice Hughes made similar findings in Abbvie Corporation v Janssen Inc, 2014 FC 55, where only the plaintiff Abbvie submitted testing of the defendant Janssen's infringing product. These two cases underscore the importance of testing evidence in patent disputes.

Utility: A "mere scintilla"

The issue of utility came down to whether the 705 Patent promised a particular utility. NOVA argued that the patent promised "synergistically enhanced physical properties" based on two statements in the patent. One statement read "surprisingly, we have now discovered compositions useful in films and molded parts having synergistically enhanced physical properties." Dow argued against such a promise.

Justice O'Keefe reviewed recent jurisprudence regarding the promise doctrine and concluded that we should look to the claims of the patent for any promised utility. Justice O'Keefe also noted that "any statement found elsewhere should be taken as a mere statement of advantage unless the inventor clearly and unequivocally states that it is part of the promised utility of the invention."

Justice O'Keefe found that the claims at issue do not include any promise of "synergistically enhanced physical properties." Justice O'Keefe then considered the expert evidence regarding whether the specification explicitly promises an enhanced utility.

Dow's expert acknowledged that the specification compared the patented compositions to traditional compositions and showed, through testing disclosed in the patent, that the patented compositions "have a balance of improved properties." The specification included statements such as "improved physical and mechanical strength" and "good impact and tensile properties." Dow's expert stated that the skilled person would understand that these statements were not promising any utility; they were simply made with respect to the comparative testing disclosed in the patent.

Justice O'Keefe accepted this evidence and found that there was no explicit promise of a specific result. Therefore, the standard for utility was a "mere scintilla." Justice O'Keefe concluded that the claimed compositions were useful.

Anticipation: Prior art must necessarily infringe; not possibly infringe

The test for anticipation applied by Justice O'Keefe was that the prior art will anticipate if it discloses subject matter which, if performed, would necessarily infringe the claims at issue.

NOVA argued that two prior patents anticipated the 705 Patent, including the Garza Patent. According to Justice O'Keefe, the Garza patent was too broad. The Garza patent asked the skilled person to make a composition by picking polymers from a number of broad categories. The skilled person could pick blends that fall within the claims of the 705 Patent. But the skilled person could also pick blends that fall outside the claims of the 705 Patent. Therefore, the Garza Patent did not necessarily fall within the claims of the 705 Patent and was not anticipatory.

Obviousness: Limiting the common general knowledge

Justice O'Keefe, referring to the Cefaclor decision, noted that the content of the skilled person's common general knowledge does not include all prior patents, patent applications, and scientific publications. There must be evidence that these prior art documents are so well known in the art as to become common stock of knowledge in the art.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.