Canada: Supreme Court Of Canada Redefines Law On Anticipation And Obviousness

Copyright 2008, Blake, Cassels & Graydon LLP

Originally published in Blakes Bulletin on Intellectual Property, November 2008


On November 6, 2008, the Supreme Court released its decision in Apotex Inc. v. Sanofi-Synthelabo Canada Inc. The primary issue before the court was the validity of selection patents. In its decision, the court upheld the validity of such patents and also established new guidelines for assessing anticipation and obviousness of patent claims.

Selection patents are directed to a specific subset or species of a known class or genus. Patents of this sort are common in, but not exclusive to, the chemical and pharmaceutical fields where a particular compound or a related set of compounds (i.e., a species) within a known class (i.e., genus) are found to have certain significant advantages over other members of the class.

Sanofi-Synthelabo Canada Inc. (Sanofi) is the owner of patent number 1,336,777 ('777) and its predecessor, patent number 1,194,875 ('875). The '777 patent is directed to clopidogrel bisulfate, which is an anti-coagulant marketed by Sanofi under the trade name Plavix. The '875 patent discloses a large genus of related compounds, including a racemate comprising clopidogrel bisulfate as well as its levo-rotatory (L) isomer. In the course of its investigation, Sanofi determined that the D isomer – clopidogrel bisulfate – exhibited higher effectiveness and lower toxicity as compared to the L isomer and the racemate, and obtained the '777 patent on this basis.

Apotex sought a Notice of Compliance (NOC) to market a generic version of clopidogrel bisulfate and, in so doing, challenged the validity of the '777 patent on various grounds including anticipation and obviousness based on the prior '875 patent. The lower courts upheld the validity of the '777 patent and Apotex appealed to the Supreme Court.

The Decision

Selection Patents

In its decision, the court first concluded that selection patents are valid in principle. The court went on to set out the following three-part test for establishing the validity of selection patents:

1. The selected members must provide some substantial advantage (or avoid some disadvantage).

2. The whole of the selected members (subject to "a few exceptions here and there") must possess the advantage in question.

3. The selection must be in respect of a quality or a special character peculiar to the selected group.

On the evidence, the court found the '777 patent to meet these criteria. In this regard, the court highlighted the high effectiveness of clopidogrel bisulfate and the reduced toxicity as compared to its L isomer or the known racemate.


Although the conditions for novelty are set forth in the Patent Act, the 1986 Federal Court of Appeal decision in Beloit Canada Ltd. v. Valmet Oy established the so-called "Beloit" test for determining anticipation. This test requires the finding of anticipation to be based on whether a single prior publication provides clear direction to a person skilled in the art to be lead to the claimed invention.

In the present case, the Supreme Court has deemed the Beloit test to be only the first step in an anticipation analysis. Specifically, the court held that anticipation requires two criteria: 1) disclosure and 2) enablement. The court explained that the Beloit test establishes only the first criterion, namely that the prior art reference must provide a disclosure of the claimed invention. However, the second criterion, namely, that of enablement requires that such disclosure must have been sufficient to enable a person skilled in the art to perform or make the claimed invention without "undue burden". In establishing this two-part anticipation test, the court recognized that, with respect to the enablement requirement, some use of "common general knowledge" and a "normal" amount of experimentation may be permissible.

In its decision, the court appears to have raised the threshold for determining anticipation by introducing the enablement requirement.

Nevertheless, after establishing and applying the two-part anticipation test, the court held that neither criterion was met by Apotex and, in the result, found the '777 patent to be novel over the prior '875 patent.


The test for obviousness also stems from the aforementioned Beloit decision, which stated that for a claim to be found obvious, a person skilled in the art and having common general knowledge must have come directly and without difficulty to the invention. In the present decision, the Supreme Court held that the Beloit test for obviousness has been interpreted too restrictively in Canada and that such definition needed to be re-examined in view of recent U.K. and U.S. law. In this analysis, the court referred to the recent KSR decision by the U.S. Supreme Court.

In its decision, the court has established a refined test for obviousness and determined that an obviousness inquiry should comprise the following four steps:

1. Identification of the relevant "person skilled in the art" and the common general knowledge that such person would have.

2. Construction of the claims in question to identify the inventive concept.

3. Identification of the differences between the construed claim and the prior art.

4. Determination of whether such differences would have been obvious to the person skilled in the art or whether they require a degree of inventiveness.

The above criteria are essentially similar to the Beloit test for obviousness. However, the court further clarified that in some instances, such as where an invention was arrived at after experimentation (as in the case in question), the last step may also involve an assessment of whether the invention was "obvious to try". In summary, the court identified at least the following four factors that may, depending on the facts, be considered in determining whether an invention was "obvious to try":

1. Is it more or less self-evident that what is being tried ought to work? That is, are there a finite number of predictable solutions that will be known to persons skilled in the art?

2. What is the nature and amount of effort required to achieve the invention? Would such effort require routine trials or prolonged experimentation?

3. Is there a motive provided in the prior art to find the solution addressed by the patent?

4. What was the course of conduct that was followed in arriving at the invention? That is, was the invention arrived at quickly and easily in view of the prior art and common general knowledge or did it involve a level of effort or knowledge above that of a skilled person?

With regard to obviousness, the court has arguably lowered the threshold by introducing an "obvious to try" test for determining inventive step. This notwithstanding, after analysing the facts and the claims of the '777 in light of the above criteria, the court found that such claims were not obvious in view of the prior '875 patent.


In this decision, the Supreme Court has provided guidance on a number of issues. First, the court has clarified the validity of selection patents by finding that where a selection, or species, is shown to have a "substantial" advantage over a known genus, it would, subject to other tests of validity, constitute patentable subject matter.

Second, the court has provided additional criteria for determining anticipation and obviousness. A new two-part test for anticipation has been proposed wherein a criterion of enablement has been added. The court has also arguably broadened the definition of obviousness by introducing an "obvious to try" criterion. As indicated above, the court has deemed the previous Beloit obviousness test to be to restrictive and has sought to bring the interpretation of obviousness in Canada in line with that of the United Kingdom and the United States.

It remains to be seen how this decision will be applied by the Canadian courts and the Canadian Intellectual Property Office.

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.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

In association with
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Mondaq Ltd requires you to register and provide information that personally identifies you, including what sort of information you are interested in, for three primary purposes:
  • To allow you to personalize the Mondaq websites you are visiting.
  • To enable features such as password reminder, newsletter alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our information providers who provide information free for your use.
  • Mondaq (and its affiliate sites) do not sell or provide your details to third parties other than information providers. The reason we provide our information providers with this information is so that they can measure the response their articles are receiving and provide you with information about their products and services.
    If you do not want us to provide your name and email address you may opt out by clicking here
    If you do not wish to receive any future announcements of products and services offered by Mondaq you may opt out by clicking here

    Terms & Conditions and Privacy Statement (the Website) is owned and managed by Mondaq Ltd and as a user you are granted a non-exclusive, revocable license to access the Website under its terms and conditions of use. Your use of the Website constitutes your agreement to the following terms and conditions of use. Mondaq Ltd may terminate your use of the Website if you are in breach of these terms and conditions or if Mondaq Ltd decides to terminate your license of use for whatever reason.

    Use of

    You may use the Website but are required to register as a user if you wish to read the full text of the content and articles available (the Content). You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these terms & conditions or with the prior written consent of Mondaq Ltd. You may not use electronic or other means to extract details or information about’s content, users or contributors in order to offer them any services or products which compete directly or indirectly with Mondaq Ltd’s services and products.


    Mondaq Ltd and/or its respective suppliers make no representations about the suitability of the information contained in the documents and related graphics published on this server for any purpose. All such documents and related graphics are provided "as is" without warranty of any kind. Mondaq Ltd and/or its respective suppliers hereby disclaim all warranties and conditions with regard to this information, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. In no event shall Mondaq Ltd and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of information available from this server.

    The documents and related graphics published on this server could include technical inaccuracies or typographical errors. Changes are periodically added to the information herein. Mondaq Ltd and/or its respective suppliers may make improvements and/or changes in the product(s) and/or the program(s) described herein at any time.


    Mondaq Ltd requires you to register and provide information that personally identifies you, including what sort of information you are interested in, for three primary purposes:

    • To allow you to personalize the Mondaq websites you are visiting.
    • To enable features such as password reminder, newsletter alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
    • To produce demographic feedback for our information providers who provide information free for your use.

    Mondaq (and its affiliate sites) do not sell or provide your details to third parties other than information providers. The reason we provide our information providers with this information is so that they can measure the response their articles are receiving and provide you with information about their products and services.

    Information Collection and Use

    We require site users to register with Mondaq (and its affiliate sites) to view the free information on the site. We also collect information from our users at several different points on the websites: this is so that we can customise the sites according to individual usage, provide 'session-aware' functionality, and ensure that content is acquired and developed appropriately. This gives us an overall picture of our user profiles, which in turn shows to our Editorial Contributors the type of person they are reaching by posting articles on Mondaq (and its affiliate sites) – meaning more free content for registered users.

    We are only able to provide the material on the Mondaq (and its affiliate sites) site free to site visitors because we can pass on information about the pages that users are viewing and the personal information users provide to us (e.g. email addresses) to reputable contributing firms such as law firms who author those pages. We do not sell or rent information to anyone else other than the authors of those pages, who may change from time to time. Should you wish us not to disclose your details to any of these parties, please tick the box above or tick the box marked "Opt out of Registration Information Disclosure" on the Your Profile page. We and our author organisations may only contact you via email or other means if you allow us to do so. Users can opt out of contact when they register on the site, or send an email to with “no disclosure” in the subject heading

    Mondaq News Alerts

    In order to receive Mondaq News Alerts, users have to complete a separate registration form. This is a personalised service where users choose regions and topics of interest and we send it only to those users who have requested it. Users can stop receiving these Alerts by going to the Mondaq News Alerts page and deselecting all interest areas. In the same way users can amend their personal preferences to add or remove subject areas.


    A cookie is a small text file written to a user’s hard drive that contains an identifying user number. The cookies do not contain any personal information about users. We use the cookie so users do not have to log in every time they use the service and the cookie will automatically expire if you do not visit the Mondaq website (or its affiliate sites) for 12 months. We also use the cookie to personalise a user's experience of the site (for example to show information specific to a user's region). As the Mondaq sites are fully personalised and cookies are essential to its core technology the site will function unpredictably with browsers that do not support cookies - or where cookies are disabled (in these circumstances we advise you to attempt to locate the information you require elsewhere on the web). However if you are concerned about the presence of a Mondaq cookie on your machine you can also choose to expire the cookie immediately (remove it) by selecting the 'Log Off' menu option as the last thing you do when you use the site.

    Some of our business partners may use cookies on our site (for example, advertisers). However, we have no access to or control over these cookies and we are not aware of any at present that do so.

    Log Files

    We use IP addresses to analyse trends, administer the site, track movement, and gather broad demographic information for aggregate use. IP addresses are not linked to personally identifiable information.


    This web site contains links to other sites. Please be aware that Mondaq (or its affiliate sites) are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of these third party sites. This privacy statement applies solely to information collected by this Web site.

    Surveys & Contests

    From time-to-time our site requests information from users via surveys or contests. Participation in these surveys or contests is completely voluntary and the user therefore has a choice whether or not to disclose any information requested. Information requested may include contact information (such as name and delivery address), and demographic information (such as postcode, age level). Contact information will be used to notify the winners and award prizes. Survey information will be used for purposes of monitoring or improving the functionality of the site.


    If a user elects to use our referral service for informing a friend about our site, we ask them for the friend’s name and email address. Mondaq stores this information and may contact the friend to invite them to register with Mondaq, but they will not be contacted more than once. The friend may contact Mondaq to request the removal of this information from our database.


    From time to time Mondaq may send you emails promoting Mondaq services including new services. You may opt out of receiving such emails by clicking below.

    *** If you do not wish to receive any future announcements of services offered by Mondaq you may opt out by clicking here .


    This website takes every reasonable precaution to protect our users’ information. When users submit sensitive information via the website, your information is protected using firewalls and other security technology. If you have any questions about the security at our website, you can send an email to

    Correcting/Updating Personal Information

    If a user’s personally identifiable information changes (such as postcode), or if a user no longer desires our service, we will endeavour to provide a way to correct, update or remove that user’s personal data provided to us. This can usually be done at the “Your Profile” page or by sending an email to

    Notification of Changes

    If we decide to change our Terms & Conditions or Privacy Policy, we will post those changes on our site so our users are always aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it. If at any point we decide to use personally identifiable information in a manner different from that stated at the time it was collected, we will notify users by way of an email. Users will have a choice as to whether or not we use their information in this different manner. We will use information in accordance with the privacy policy under which the information was collected.

    How to contact Mondaq

    You can contact us with comments or queries at

    If for some reason you believe Mondaq Ltd. has not adhered to these principles, please notify us by e-mail at and we will use commercially reasonable efforts to determine and correct the problem promptly.

    By clicking Register you state you have read and agree to our Terms and Conditions