Copyright 2010, Blake, Cassels & Graydon LLP
Originally published in Blakes Bulletin on Intellectual Property, August 2010
The Federal Court of Appeal recently confirmed that a selection patent is to be given the same treatment as any other patent in terms of assessing its validity. The court denied a separate ground of invalidity based on a patent being an "improper selection patent".
A selection patent is a patent granted for an invention based on the recognition that a particular selection of individual elements, subsets, or sub-ranges, within a larger, known set or range has benefits. Although not restricted to chemical patents, selection patents more commonly arise in that context. Simply stated, the patent typically refers, in general terms, to a group of products or processes from all of which a particular result (or results) may be obtained or predicted. Selection patents exist to encourage researchers to further use their inventive skills so as to discover new advantages for compounds within the known class. A selection patent can be claimed for a selection from a class of thousands or for a selection of one out of two.
Test for a Valid Selection Patent
In 2008, the Supreme Court of Canada, in Apotex Inc. v. Sanofi-Synthelabo Canada Inc., described a valid selection patent as follows:
- there must be a substantial advantage to be secured or disadvantage to be avoided by the use of the selected members;
- the whole of the selected members, subject to "a few exceptions here and there", possess the advantage in question; and
- the selection must be in respect of a quality of a special character peculiar to the selected group. If further research revealed a small number of unselected compounds possessing the same advantage, that would not invalidate the selection patent. However, if research showed that a larger number of unselected compounds possessed the same advantage, the quality of the compound claimed in the selection patent would not be of a special character.
The question that still remained was at what stage, or where, are the noted conditions for a valid selection patent to be addressed. This was square before the Federal Court of Appeal in 2010 in Eli Lilly Inc. et. al v. Novopharm Ltd. Eli Lilly commenced an action in the Federal Court against Novopharm for infringement under Canadian Patent No. 2,041,113, of a selection patent for the compound olanzapine, sold under the brand name Zyprexa. Olanzapine is used to treat schizophrenia.
As part of its defence, Novopharm asserted that the patent at issue was invalid on various grounds, including anticipation, double patenting, and obviousness. One basis for attack was that the patent in suit was not a valid selection patent.
After a 44-day trial, the trial judge agreed with Novopharm and concluded that the patent in suit was not a valid selection patent. In rendering his decision, Justice O'Reilly did not consider the elements of the Sanofi approach. Instead, he proceeded on the basis that, in order to uphold the patent in suit as a valid selection patent, he must satisfy himself that olanzapine has an advantage over the other compounds disclosed in an earlier, now expired, Eli Lilly patent which encompassed, but did not disclose, olanzapine. Further, the advantage must be substantial and somewhat peculiar to olanzapine and the patent in suit must clearly describe the substantial and special advantage.
The trial judge concluded that olanzapine fell within the "most preferred" compounds of that earlier patent, which specifically disclosed flumezapine, ethyl flumezapine and ethyl olanzapine.
Although recognizing that the patent at issue had advantages over the earlier patent, the trial judge concluded that there was insufficient evidence of the advantages identified in the patent in suit. Specifically the trial judge determined that: the stated advantages were not substantial and peculiar; a person skilled in the art would not be able to appreciate any inventive difference between the earlier patent and the patent in suit; the test for sound prediction was not met; Eli Lilly had very little idea about what olanzapine's effect was likely to be; and the patent in suit did not meet the requirements for adequate disclosure.
The Appeal Decision
On appeal, Eli Lilly argued that Justice O'Reilly erred by creating an "illegitimate amalgam by merging the doctrine of sound prediction of utility with obviousness and sufficiency and in the process required [Eli] Lilly to provide proof of the inventive step (i.e. the advantages) in the disclosure." Specifically, Eli Lilly argued that, in a selection patent, the advantages are part of the invention. Hence, if advantages are not established, there is no invention. Eli Lilly argued that the "selection" issue goes to the question of obviousness and is properly addressed as part of that inquiry.
The Federal Court of Appeal agreed with Eli Lilly and noted that a challenge directed to a determination that the conditions for a selection patent have not been met "does not constitute an independent basis upon which to attack the validity of a patent". Rather, the conditions for a valid selection patent serve to characterize the patent and inform the analysis for the grounds to attack its validity.
However, the validity of a selection patent is vulnerable to attack on any of the grounds set out in the Patent Act – novelty, obviousness, sufficiency and utility. In short, a selection patent is the same as any other patent when it comes time to assess its validity. The Federal Court of Appeal also noted that the Patent Act contains no reference to invalid selection. It necessarily followed that the trial judge erred in determining the validity of the patent in suit on the basis that he did. Given the manner in which the trial judge had proceeded, the Federal Court of Appeal determined that there were insufficient factual determinations in the trial judgment to conduct a meaningful review on the issues of utility and sufficiency. Accordingly, the case was remitted to the trial judge for a determination on these matters.
In recent years, there have been a number of cases where an alleged infringer has attacked a selection patent on the basis of improper selection, especially in the pharmaceutical context where such patents are more prevalent. This case appears to close the door to such attacks and will require defendants to focus and rely on traditional validity attacks.
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