In the latest installment of the CIALIS® (tadalafil) PM(NOC) saga, Apotex Inc. asked the Federal Court of Appeal to depart from a recent judgment by a different panel of the same court (covered previously on our blog here) on the ground that the judgment did not follow the Supreme Court of Canada’s decision in Whirlpool Corp. v. Camco Inc., 2000 SCC 67, insofar as the date for double patenting is concerned. The FCA ultimately dismissed the appeal, noting that Whirlpool did not settle the question at issue, and thus the principles articulated in Miller v Canada, 2002 FCA 370, which recognize the right of the Court to overrule its prior jurisprudence, did not apply. The FCA’s full decision is available here: Apotex Inc. v. Eli Lilly Canada Inc., 2016 FCA 267.

The appeal stems from the lower Court’s decision granting Eli Lilly Canada Inc.’s application for an order prohibiting the Minister of Health from issuing a Notice of Compliance to Apotex until the expiry of Lilly’s ‘784 Patent. Apotex had unsuccessfully alleged that the ‘784 Patent, which claimed tadalafil for the treatment of erectile dysfunction, was invalid for double patenting over Lilly’s earlier ‘377 Patent, which claimed the compound tadalafil itself.

During the proceeding with Apotex, Lilly faced an identical challenge from Mylan Pharmaceuticals ULC. Lilly’s application for a prohibition order in that proceeding was successful, and was upheld on appeal in Mylan Pharmaceuticals ULC v. Eli Lilly Canada Inc., 2016 FCA 119. The argument turned on the date at which the double-patenting comparison is to be conducted because of changes in the state of the art, and hence the understanding of the skilled person, between those dates.

Several days after the FCA’s judgment in the Mylan case issued, the present appeal was heard. Similar to the Mylan appeal, the key issue in this case was the date of the double-patenting analysis. By way of overview, the FCA explained the various dates relevant in patent law:

“The first is the priority date which is the date of an international filing, or of another Canadian filing, as of which a Canadian patent application claims priority. The second is the filing date, which is the date of the filing of the patent application in the Canadian patent office. Not every patent has a priority date but all have a filing date. The last date is the publication date of the patent, which occurs at the end of a confidentiality period of 18 months – which can be shorter at the applicant’s request – which begins on the earlier of the priority date or the filing date of a patent.”

The sole double-patenting issue on appeal was whether Whirlpool decided that the date for comparison of the claims in an obviousness-type double-patenting case is the publication date of the later-issued patent. The FCA noted that if this argument by Apotex is correct, “both Apotex FC and Mylan FCA (and, by extension, Mylan FC) are wrongly decided.”

In Whirlpool, two patents relating to washing machines were the subject of the double-patenting analysis. Writing for the SCC, Justice Binnie made several references to the publication date of the later patent when discussing the state of the art. Apotex argued that these repeated references to the publication date of the later patent suggest that Justice Binnie would have also assessed double-patenting as of that date.

The FCA rejected Apotex’s argument. Justice Pelletier noted that the issue of the date for the double-patenting analysis had not arisen previously in the SCC or in the secondary literature and that it is “improbable that Binnie J. would settle a significant point in the law of double patenting by implication and without addressing it directly”.

While the parties in this appeal framed the issue of double patenting in terms of the dates of the analysis, the FCA cautioned that it should not be viewed as having decided that this is the only approach, or even the correct approach:

“Perhaps, the Court, having construed the claims of each of the patents with the assistance of the persons skilled in the art, simply compares the claims and decides whether the later claims are patentably distinct from the earlier claims on the basis of the insights which it has gained in the course of the construction of the patents.”

The “insights” which the Court has “gained in the course of the construction of the patents” will relate to two dates – the publication date of the earlier patent and the publication date of the later patent. However, the FCA does not say that the “insights” gained as of the later publication date are necessarily relevant. The Federal Court and the Federal Court of Appeal have been hesitant to conclusively decide the date on which the double-patenting analysis is to be conducted even in situations where the issue was squarely before these Courts and argued in full. It will be interesting to see if, given the opportunity, the SCC addresses this significant point in the law of double-patenting.