On July 24, 2013, the Federal Court of Appeal (FCA) issued its decision in Apotex Inc. v. Sanofi-Aventis, overturning a Federal Court decision invalidating Canadian Patent No. 1,336,777 (’777 Patent) - a patent owned by Sanofi claiming the active ingredient of the drug Plavix (clopidogrel bisulfate). This decision is the latest step in a lengthy history of proceedings between the parties, including an appeal to the Supreme Court of Canada (SCC), which held that the ’777 patent was valid. As that SCC decision was in the context of the Patented Medicines Notice of Compliance (PM(NOC)) proceeding, the finding was not (strictly speaking) binding on the Federal Court. It was still surprising that the Federal Court subsequently decided to invalidate the patent. The FCA decision points out the errors of the Federal Court and clarifies the law on the promise of the patent.

In order for an invention to be patentable in Canada it must be new, inventive and have utility. (This is true under both the pre-October 1, 1989 Patent Act (the Old Act, which the ’777 Patent was subject to) and the post-October 1, 1989 Patent Act.) Generally speaking, the threshold for meeting the utility requirement is quite low; absent a promise in the patent, a “mere scintilla” of utility will suffice. On the other hand, when a patent sets out an “explicit” promise, the utility of the invention will be assessed against such a promise. If the invention does not meet the stated promise – the patent will fall for lack of utility.

The FCA reiterated that not every patent contains an explicit promise of utility and that there is no legal obligation to disclose the utility of the invention in the patent. Selection patents are an exception to this disclosure requirement. The utility requirement of a selection patent is met by the selected compounds having an unexpected advantage over the other compounds in the genus and by disclosing such unexpected advantages in the patent. The ’777 Patent is considered to be a selection patent because it claims a subset of compounds that fall within the scope of the teachings and claims of an earlier genus patent. 

The trial judge concluded that the ’777 Patent contained an “explicit promise” regarding the use of the compounds in humans (i.e., that the compounds will be useful in humans). The trial judge came to this conclusion by drawing inferences from various statements in the patent, for example, the references to the “medicine of the invention” and that the “medicine of the invention can be usefully administered in the treatment and prevention of platelet disorders…”.

The FCA held that the trial judge erred in law by reading this promise into the patent. The FCA stressed that courts should not strive to find ways to defeat otherwise valid patents. In other words, the courts should avoid reading a promise into a patent where one does not explicitly exist.

In reaching its decision, the FCA emphasized the distinction between the potential use of an invention and an explicit promise of a specific result, noting that inferences, goals, hopes and potential applications are not promises. The FCA concluded that the trial judge “erred in law in reading into the ’777 Patent a promise for use in humans 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” (emphasis added). The “clear and unambiguous” statements referred to by the FCA include statements such as “[i]n an unexpected manner only the [selected] enantiomer exhibits a platelet aggregation inhibiting activity, the [unselected] enantiomer being inactive. However, the inactive [unselected] enantiomer is the less well tolerated of the two enantiomers.”

In other words, the FCA concluded that the patent did not promise that the compounds would be useful in humans. According to the FCA, all the patent promised was that the selected compounds had greater platelet aggregation inhibiting activity and were less toxic than the unselected compounds. The patent had data to support such a promise. Therefore, the patent was not invalid for lack of utility.

Justice Gauthier, in his concurring decision, also noted that Canadian applications filed on the basis of European applications will often contain statements regarding the invention’s industrial application because European patent law requires the invention be capable of industrial application. Justice Gauthier cautions that “one must be careful not to treat each reference to a practical purpose as a promise of a specific result…”.

Though it is still possible for Apotex to seek leave from the SCC to appeal this decision, it is unlikely that such leave will be granted. The SCC has already issued a decision regarding the validity of this particular patent, albeit in the context of a PM(NOC) proceeding, and this particular utility issue was not raised. The SCC may be reluctant to have another hearing to again decide the validity of this patent.

On a strict reading of the FCA’s decision, absent an explicit promise, i.e., a clear and unambiguous statement, it will be very difficult to find that a patent promises any particular utility. Absent an “explicit promise”, all the patentee must show is that the invention has the merest scintilla of utility.