The test for obviousness in Canada was outlined over 20 years ago by the Federal Court of Appeal in the Beloit Canada Ltée/Ltd. v. Valmet Oy1 decision, which requires a person skilled in the art to “have come directly and without difficulty to the solution taught by the patent”. As noted in the Beloit case, “[i]t is a very difficult test to satisfy”.

In November 2008, the Supreme Court of Canada in the case Sanofi-Synthelabo Canada Inc. v. Apotex Inc.2 was asked to re-visit this classic definition in order to make Canadian law more consistent with recent decisions rendered in the United States and the United Kingdom. The question at issue was whether the previous disclosure of a racemate mixture (a mixture of stereoisomers) would make a patent to the dextro-rotatory isomer of the racemate “obvious to try”. After citing the approach taken by the English Court of Appeal in the Generics (UK) Ltd. v. H. Lundbeck A/S3 decision, Justice Rothstein for the Supreme Court of Canada agreed that the incorporation of an “obvious to try” test into Canadian law was appropriate in some circumstances and suggested a similar non-exhaustive list of factors as those cited in the U.K. Generics decision. More particularly the Supreme Court cited factors including: (i) expectation of success (the number of identified predictable solutions) (ii) the amount of effort required (whether the trial be considered routine) and (iii) the motivation to try. It was also noted that the course of conduct culminating in the invention may also be an important factor. In applying this test to the facts, the Supreme Court upheld the PLAVIX patent in issue as being non-obvious.

It has not taken long for the newly introduced “obvious to try” test to be re-interpreted, and arguably re-written, by Canadian courts. In the Federal Court of Appeal’s Jan. 16, 2009 decision dealing with Pfizer’s VIAGRA patent in Apotex Inc. v. Pfizer Canada Inc.4 , the Federal Court of Appeal dealt with the issue of obviousness in light of the revision to the law by the Supreme Court of Canada in the Sanofi decision. Apotex relied heavily on the U.K. Generics decision, which had invalidated the VIAGRA patent in the U.K. on the grounds of obviousness. Ironically, the Federal Court of Appeal in Apotex characterized the test in the U.K. as being “worth a try” and therefore different from the “obvious to try” test adopted by the Supreme Court in Canada in Sanofi. In doing so, the Federal Court of Appeal in Apotex relied on comments by the Supreme Court of Canada in Sanofi in stating that the “obvious to try” test “will work only where it is very plain or, … more or less self-evident that what is being tested ought to work”5. On this basis, the Federal Court of Appeal argued that unlike the law in the U.K., even a very high degree of motivation could never replace the requirement that the solution must be “predictable” or provide “a fair expectation of success”.6

It therefore appears that the factors introduced by the Supreme Court of Canada in Sanofi are not all to be considered equally. Rather, one must first determine whether there is a fair expectation of success before weighing the other relevant factors. Whether this interpretation was the one intended by the Supreme Court of Canada Court in Sanofi may have to await an appeal, if one is forthcoming, on the Federal Court of Appeal’s decision in Apotex.