Canada’s Intellectual Property Firm

Federal Court of Appeal reverses inutility and obviousness findings re: PLAVIX patent

by Tracey L. Stott

On July 24, 2013, the Federal Court of Appeal overturned Justice Boivin’s decision which had invalidated the patent that claims clopidrogel bisulfate (sanofi-aventis's PLAVIX) on the basis of lack of utility and obviousness. The Court returned the issues of remedies to the Trial Judge.

The same patent (777) had previously been the subject of litigation under the Patented Medicines (Notice of Compliance) Regulations. As reported in the November 2008 special edition of Rx IP Update, the Supreme Court of Canada upheld the Order of prohibition preventing the Minister of Health from issuing a notice of compliance ("NOC") to Apotex (2008 SCC 61). Following its loss in the Supreme Court, Apotex brought an impeachment action, and sanofi-aventis followed with an infringement action which resulted in Justice Boivin’s decision under appeal.

The 777 patent discloses and claims the enantiomer clopidogrel and its bisulfate salt, as well as processes for its manufacture. An earlier patent (875) encompassed clopidogrel bisulfate within its claims and included an example describing the racemate. The claims also referred to enantiomers.

The Court of Appeal considered whether the patent contained an explicit promise that the invention could be used in humans, whether resolution of the racemate was “obvious to try,” and certain defences to infringement. The majority reasons were written by Justice Pelletier. In a concurring decision, Justice Gauthier agreed with the majority and also commented on utility and obviousness.


The Court stated that not every patent contains an explicit promise of a specific result, since there is no obligation on the part of the inventor to disclose the utility of the invention in the patent. The first step in analyzing utility is to determine if a skilled person would understand the patent to contain an explicit promise of a specific result. If so, the inventor will be held to that promise; if not, a mere scintilla of utility will do. The Court, citing the Supreme Court’s decision in Consolboard Inc v MacMillan Bloedel (Saskatchewan) Ltd, [1981] 1 S.C.R. 504, emphasized that “[C]ourts should not strive to find ways to defeat otherwise valid patents.”

The Trial Judge described the invention as “a compound which is useful in inhibiting patelet aggregation, has greater therapeutic effect and less toxicity than the other compounds of the 875 Patent, has the advantages of the salts…and the methods for obtaining that compound.”

The Trial Judge concluded that studies performed by sanofi-aventis demonstrated the existence of these advantages; the Court of Appeal held that the utility attack should therefore have failed. However, the Trial Judge went on to find that the patent made an explicit promise for use in humans. The Court stated that the Trial Judge erred in reading in this promise “on the basis of inferences, in the absence of language at least as clear and unambiguous as that used to establish the advantages of the selection over the compounds of the genus patent.” Based on the evidence, the Court held that the skilled person would understand that “alluding” to the possibility of potential use in humans was not a promise that this result had been or would be achieved.

The Court also held that the Trial Judge’s further justification for his construction based on reference to such use in the genus patent was incorrect for two reasons. First, a patent should not be construed with “an eye to validity.” Second, the Trial Judge had found that the 777 patent described the advantages over the genus patent and the advantages were demonstrated; thus, the 777 patent is a valid selection patent regardless of whether there was a promise for use in humans. The “unexpected advantage” of a selection patent need not be an improvement on every aspect of the genus patent – it is enough that the invention is a new and useful improvement on “some aspect.”

In her concurring reasons, Justice Gauthier cautioned that not all references to a “practical purpose” should be treated as a promise of a specific result. Given the skilled person’s knowledge that one cannot reasonably predict any useful use of clopidogrel in humans from the properties and advantages demonstrated in the patent, the skilled person would also recognize that the mechanism and properties identified in the patent were insufficient to conclude that a practical application in humans will indeed be achieved. Thus, she construed “can” within the context of “...the medicine of the invention can be usefully administered in the treatment and prevention of platelet disorders…” to indicate “potentially capable of.” In her view, even if the Trial Judge’s construction of the promise was correct, the promise had been met as clopidogrel is useful in humans.

She distinguished the invention in the 777 patent from a new use (such as the invention at issue in the AZT case), where the quid pro quo for the grant of the monopoloy was full disclosure of such utility. Here, the public has received all the information necessary to make and use clopidogrel and the advantages necessary for a selection inventive were fully and properly described and demonstrated in the patent. In such a case, the level of disclosure required should be lower: the clear indication that use in humans was predicted as opposed to demonstrated should be sufficient at law to meet the test for sound prediction.


The Court reviewed the Supreme Court’s determination that the invention of the 777 patent was not obvious, in which the “key factor” was “the lack of knowledge of the properties of the enantiomers of the compounds” of the genus patent. The Trial Judge, in contrast, focused “exclusively” on the question of whether it was obvious to try to resolve the racemate.

The Trial Judge had found that the properties of the enantiomers were unpredictable, which the Court stated was “precisely what led the Supreme Court…to hold that it was not self-evident that what was being tried ought to work.” Thus, the Court reasoned that as the Trial Judge applied the test for obviousness articulated by the Supreme Court to the same material facts, he ought to have come to the same conclusion – i.e., the invention was not “obvious to try.”

Justice Gauthier emphasized the importance of considering the whole course of conduct leading to the decision to separate noting the Trial Judge did not find that the skilled person would obviously start a development project based on the 875 patent with the racemate containing clopidogrel as opposed to any other compound and sanofi’s actual course of action militated against such a conclusion.


Apotex did not contest infringement on appeal, but argued that sanofi should be precluded from recovering damages. The Court of Appeal upheld the Trial Judge’s rejection of Apotex’s arguments regarding limitation period and experimental and regulatory use. The Court also upheld the Trial Judge’s rejection of Apotex’s reliance on a liability exposure provision in a U.S. settlement. The Court of Appeal held that Apotex lost the benefit of the provision when it chose to attack sanofi’s patent.

If Apotex wishes to appeal this decision, leave must be granted by the Supreme Court of Canada.

Federal Court decision - Apotex Inc v sanofi-aventis 2011 FC 1486, reported in the January 2012 edition of RxIP Update

Court of Appeal decision - sanofi-aventis v Apotex Inc, 2013 FCA 186.

The preceding is intended as a timely update on Canadian intellectual property and technology law. The content is informational only and does not constitute legal or professional advice. To obtain such advice, please communicate with our offices directly.