Apotex Inc v Sanofi-Synthelabo Canada Inc, 2008 SCC 61
Sanofi-Synthelabo (Sanofi) marketed the drug product PLAVIX, which contained as the active ingredient, clopidrogrel bisulfate, an anti-coagulant that inhibited platelet aggregation activity in the blood. Clopidogrel was covered by two Canadian patents, Canadian Patent No 1,194,875 (the 875 Patent) and Canadian Patent No 1,336,777 (the 777 Patent). The 875 Patent was filed in 1983 and expired in 2003. The 777 Patent was filed in 1988 and expired in 2012.
The 875 Patent disclosed a genus or class of compounds including approximately 250,000 compounds. The 777 Patent was referred to a “selection patent” because it claimed and described a selected member of this class, namely, clopidogrel.
In 2003, Apotex sought to make a generic version of PLAVIX before the expiry of the 777 Patent. Thus, through the procedure dictated by the Patented Medicines (Notice of Compliance) Regulations, Apotex alleged that the 777 Patent was invalid because clopidogrel was anticipated (not new), obvious, and a double patent in light of the earlier 875 Patent.
The issue before the Supreme Court of Canada (SCC) was whether selection patents were invalid in principle or the 777 Patent was invalid on the facts of the case. In its reasons for the decision to uphold the validity of the 777 Patent, the SCC imported legal principles from cases in the United Kingdom and the United States in order to deal with selection patents.
The SCC confirmed that in Canada a system of genus and selection patents was acceptable in principle, following the line of cases beginning with In Re I G Farbenindustrie AG’s Patents (1930), 47 RPC 289 (Ch D). Thus, the question was whether, on the facts presented in the case, the 777 Patent specifically was anticipated, obvious or a double patent.
The SCC first refined the test of anticipation set out in the Canadian case of Beloit Canada Ltd v Valmet Oy (1986), 8 CPR (3d) 289. Following the reasoning in the UK case Synthon BV v SmithKline Beecham plc,  1 All ER 685,  UKHL, the SCC stated that there were two requirements for a finding of anticipation: prior disclosure and enablement.
Applying this test to the facts of the case, the SCC concluded that the 875 Patent did not disclose the invention of the 777 Patent, clopidogrel, which was a compound having better properties than other compounds in the 875 Patent. As a result, the 777 Patent was not anticipated by the 875 Patent.
The SCC then sought to bring better structure and more objectivity and clarity to the obviousness analysis by introducing into Canadian law the four-step approach used in the UK case Pozzoli SPA v BDMO SA,  FSR 37,  EWCA Civ 588, which was an update to the approach in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd,  RPC 59 (CA). Relying on the reasoning of the UK and US cases, the SCC further stated that it may be appropriate to consider certain “obvious-to-try” factors in some circumstances as part of this approach.
Conducting this analysis in this case, the SCC concluded that the subject matter of the 777 Patent was not obvious from that of the 875 Patent.
Finally, with respect to the issue of double-patenting, the SCC held that the claims of the 777 and 875 Patents were not directed to the “same invention” since the 777 Patent claimed a narrower invention, and it was found clopidogrel was disclosed to have better properties. Therefore, Apotex’s allegation of invalidity on that ground failed.
Heather Watts highlights the key points of the case:
Sanofi-Synthelabo was a defining case regarding the status of selection patents under Canadian law. It also modified the tests for obviousness and anticipation set out in the previous leading case Beloit Canada Ltd v Valmet Oy (1986). This decision provided for an analytical approach to obviousness and the opportunity to argue that inventions won by experimentation would have been obvious to try. The decision also clarified that in order for a single prior art document to anticipate, it must both disclose and enable the claimed invention. As a result of this decision, the test for obviousness arguably became easier to meet in some cases, while the test for anticipation became more stringent.
A more detailed discussion about the legal concepts of this case was previously reported in E-TIPS® here.
Summary by: Cheryl Cheung