Case: Sanofi-aventis et al. v. Apotex Inc. et al.
Drug: Clopidogrel (PLAVIX®)
Nature of case: Patent infringement and validity
Successful party: Sanofi-aventis et al.
Date of decision: July 24, 2013


The Federal Court of Appeal has allowed an appeal by Sanofi-aventis et al. (“Sanofi”) of a decision declaring Canadian Patent No. 1,336,777 (“777 Patent”) to be invalid for lack of utility and obviousness.  This decision is significant in respect of the application of the concept of the “promise of a patent”, part of the “utility” test in Canadian patent law.

The Federal Court of Appeal decided that the Trial Judge erred in drawing inferences and reading use in humans into the patent’s promise.  As the Federal Court of Appeal states in its decision, “properly construed, the ‘777 Patent made no such promise.”

The Federal Court of Appeal also overturned the Trial Judge’s decision on obviousness, adopting the reasoning by the Supreme Court of Canada in a separate proceeding Apotex Inc. v. Sanofi-Synthelabo Canada Inc. (2008 SCC 61) (“Plavix”) which was based on the same material facts put before the Trial Judge and pertained to the same patent, the 777 Patent.   The Federal Court of Appeal found that the distance between the common general knowledge and the inventive concept of the 777 Patent could not be bridged by routine experimentation since the results to be obtained were unknown.

The Federal Court of Appeal also rejected grounds to limit Sanofi’s right of recovery raised by Apotex Inc. (“Apotex”), namely the limitation defence, a U.S.-based settlement agreement and the exemption from infringement that permits experimental and regulatory use. 

Prior related proceedings

In an earlier proceeding, Sanofi brought an application pursuant to section 6 of the Patented Medicines (Notice of Compliance) Regulations (“PM(NOC) Regulations”) for an order prohibiting the Minister of Health from issuing a Notice of Compliance to Apotex in respect of its clopidogrel bisulfate (the “Apotex Product”) until the expiry of Canadian Patent No. 1,336,771 (the “771 Patent”).  Sanofi was successful in obtaining the prohibition order, and appeals to both the Federal Court of Appeal and the Supreme Court of Canada in Plavix by Apotex were dismissed.

The precursor to this appeal is an action at the Federal Court seeking a declaration of invalidity of the 777 Patent commenced by Apotex following its unsuccessful run in the related proceedings pursuant to the PM(NOC) Regulations.  Sanofi responded by commencing an infringement action against Apotex for the import of clopidogrel into Canada from Mexico and the export of clopidogrel from Canada to the United States.  Both actions were ultimately consolidated.

The 777 Patent

The 777 Patent claims a selection from Canadian Patent No. 1,194,875 (“875 Patent”), which discloses a genus or class of compounds useful in inhibiting platelet aggregation activity in the blood.  The 875 Patent discloses over 250,000 possible different compounds.  Clopidogrel bisulfate, claimed by the 777 Patent, is encompassed within the scope of the claims of the 875 Patent.  Clopidogrel bisulfate is the dextro-rotatory isomer (enantiomer) of a racemate (a mix of two mirror image enantiomers, the dextro- and the levo- rotatory isomers).

Construction of “the Promise”

The Trial Judge had erred in construing the promise to include use in humans. There was no explicit promise that the claimed compound would work in humans. The Trial Judge inferred a promise from statements made in the patent in the absence of clear and unambiguous language.

The studies available at the time of patent filing were limited to tests in rats, mice and baboons, and demonstrated the existence of the advantages identified by the inventors for the selection in the 777 Patent: a compound which is useful in inhibiting platelet aggregation, has greater therapeutic effect and less toxicity than the other compounds of the 875 Patent.  As a consequence of the Trial Judge’s version of the  promise of the 777 Patent (an “explicit  promise” for use in humans), the 777 Patent was found to be invalid as the “construed” promise had not been demonstrated nor soundly predicted.

In finding that the Trial Judge also erred in finding that the patent was invalid for lack of utility, the Court of Appeal observed that “Courts should not strive to find ways to defeat otherwise valid patents.”

In concurring reasons, Justice Gauthier highlights a statement by Professor Norman Siebrasse to the effect that “Binnie J’s brief statement at paragraph 70 of AZT is not a proper basis for the heightened level of disclosure applied in recent case law, especially in cases where no use or specific result is referred to in claims where the inventor defines the invention for which he is seeking a monopoly, or where a specific advantage/utility is required to support the right to claim a particular invention (selection).”

The Court of Appeal also confirmed that the unexpected advantage (i.e. utility) of a selection need not be an improvement on every aspect of the invention described in the genus patent.  It is enough that the selection is an improvement on some aspect of the original invention.


While the methods of separation of a racemate were part of the common general knowledge and the enantiomer clopidogrel was known and part of the common general knowledge, the enantiomer’s properties were not known and not part of the common general knowledge.  Despite this, the Trial Judge found that resolving the enantiomer clopidogrel was obvious to try.

The key facts at issue in this proceeding were previously before the Supreme Court of Canada in Plavix.  The principal factor in the Supreme Court’s analysis of “obvious to try” was the lack of knowledge of the properties of the enantiomers of the compounds encompassed by the 875 Patent.

The Court of Appeal agreed that the resolution of the racemate of a known compound cannot be obvious to try if the properties of the enantiomers were unknown. Routine experimentation cannot bridge the gap between the common general knowledge and the claimed enantiomer if the results to be obtained were unknown.

The Court of Appeal concluded that the Trial Judge erred in finding that the selection was “obvious to try” and that the patent was invalid.


The finding of infringement of the 777 Patent was not appealed by Apotex. However, the Court of Appeal did consider whether Sanofi was precluded from recovering damages for the infringement on the following grounds raised by Apotex: (1) appropriate limitation period; (2) possession of the compound for experimental and regulatory use; and (3) settlement and estoppel.

The Court of Appeal found that the Trial Judge had properly applied a 6 year limitation period pursuant to Section 39(2) of the Federal Courts Act which applies to causes of action “arising otherwise than in a province.”  Apotex argued that the cause of action arose in Ontario since the ports of entry and departure were in Ontario and that the laws relating to prescription and the limitations of actions in Ontario should apply.   The Court of Appeal upheld the Trial Judge’s decision based on the fact that patents confer monopolies across Canada and the import or export of goods into or out of Canada is what constituted infringement.  As a result, none of Sanofi’s claim was statute barred.

The Court of Appeal upheld the Trial Judge’s inference that the product had been sold following the regulatory use since there was no evidence proffered to the contrary (ie. documentation providing proof of destruction of product).

The Court of Appeal upheld the Trial Judge’s decision that settlement in the United States of litigation in respect of a different patent for the same (or similar) compound could not be used to limit liability in Canada. The Court of Appeal acknowledged the equitable rule against double recovery but indicated that there was no evidence of whether the US and Canadian infringements are, in fact or in law, the same loss.

Link to decisions:

The Federal Court of Appeal decision may be found at:

The Federal Court decision may be found at: