Tuesday, August 20, 2013

Promise of Utility in Canadian Patent Law

Tuesday, August 20, 2013
What is the Promise of Patent?

On July 24, 2013, the Federal Court of Appeal issued its judgment in relation to Sanofi’s Canadian Patent No. 1,336,777 (the ‘777 patent) directed to the blockbuster anti-coagulating drug Plavix®.

The ‘777 patent is a selection patent that claims a subset of compounds already encompassed by Canadian Patent No. 1,194,875 (the genus patent). The active ingredient in Plavix® is the dextro-rotary isomer of clopidogrel, which exhibits beneficial properties over both the racemate and the levo-rotatory isomer.

The case began in 2005 when Apotex filed a Notice of Allegations pursuant to the Patented Medicine Notice of Compliance Regulations (“PMNOC”) alleging that the ‘777 patent was invalid. This PMNOC case was ultimately heard by the Supreme Court of Canada in 2008. The Supreme Court found that Apotex’s invalidity allegations were without merit.

Apotex and Sanofi then commenced separate actions in the Federal Court. Apotex again alleged that the ‘777 patent was invalid, while Sanofi asserted that Apotex infringed its clopidogrel patent. The separate actions were consolidated in 2011 and went before the trial judge Justice Boivin who declared that the ‘777 patent was invalid because it lacked utility and was obvious to an ordinary person skilled in the art.

The decision of Justice Boivin was appealed. The Court of Appeal reversed Justice Boivin’s findings on both utility and obviousness. The Court of Appeal’s finding on obviousness is insightful, but the more substantive part of the ruling relates to the legal concept of “promise of utility.” In Canadian patent law, at the time of application filing, a patent must either demonstrate utility or soundly predict utility of the invention. The utility is also measured by the promise of the patent:
Where the specification does not promise a specific result, no particular level of utility is required; a "mere scintilla" of utility will suffice. However, where the specification sets out an explicit "promise", utility will be measured against that promise: The question is whether the invention does what the patent promises it will do.
The trial judge’s finding of inutility was based on his conclusion that the promise of the ‘777 patent was that clopidogrel could be used in humans. In addition to giving weight to Apotex’s expert evidence, which said that the ‘777 patent clearly referred to some human diseases and conditions, Justice Boivin arrived at his conclusion by making inferences; such as “the fact that clopidogrel is to be administered by oral, rectal or parenteral administration” and the usage of words like “patients” in the patent. Justice Pelletier and Gauthier at the Federal Court of Appeal, rejected the trial judge’s inference of a promise of utility to invalidate the ‘777 patent. Justice Pelletier cited the following remarks from AstraZenaca v. Mylan Pharmaceuticals:
I accept AstraZeneca's argument that not all statements of advantage in a patent rise to the level of a promise. A goal is not necessarily a promise. The third paragraph of the 420 Patent refers to a forward looking goal, a hoped-for advantage of the invention. 
Justice Gauthier augmented that “one must be careful not to treat each reference to a practical purpose as a promise of a specific result within the meaning of Consolboard".

The Court of Appeal held that the trial judge did not err in his finding that inferences were made which point to the prospect of clopidogrel being used in humans, but rather erred in his construction of the promise made in the patent. Most if not all pharmaceutical patents have the ultimate goal or aspiration of being applied to humans. However, as the Court of Appeal rightly ruled, these goals cannot be construed as specific promises to which the validity of the patent is measured against.

Going back to first principle, the Court of Appeal painted the context before they began analyzing the validity of the patent. This is congruent with the purposive approach to constructing patent claims laid down in Whirlpool Corp. v. Camco Inc. The trial judge erred when he failed to take into the context in which drug patents are drafted.

In my opinion, the Federal Court of Appeal has provided helpful guidance in delineating between a promise of utility and a goal when determining the utility standard that a patent is measured against.

By David Chen
Articling Student