Apotex Fails to Change FCA’s Opinion in Tadalafil Case

Apotex Fails to Change FCA’s Opinion in Tadalafil Case

Apotex Inc v Eli Lilly Canada Inc, 2016 FCA 267

Courts have yet to clarify which date is to be used in comparing the claims of two patents. In this Federal Court of Appeal (“FCA”) decision, the appellant, Apotex Inc. (“Apotex”), sought to show, unsuccessfully, that the FCA had erred in the recent case of Mylan Pharmaceuticals ULC v Eli Lilly Canada Inc, 2016 FCA 119 [Mylan FCA] (PCK Reporter summary available Here). Apotex argued that the FCA had not followed the Supreme Court decision of Whirlpool Corp v Camco Inc, 2000 SCC 67 [Whirlpool]. [1] Additionally, the appellant argued that the Federal Court (“FC”) erred in its finding that the disclosure in the patent in question was sufficient to teach a person of ordinary skill in the art (“POSITA”) to make the invention. [3]

The decision was in relation to Canadian Patent No. 2,226,784 (“the ‘784 Patent”). [1] Entitled “Use of cGMP-Phosphodiesterase Inhibitors to Treat Impotence,” it claimed the usage of tadalafil in treating erectile dysfunction (“ED”). [1] The decision was also the fourth to revolve around whether the ‘784 Patent contained “patentably distinct” claims, in relation to an earlier patent covering tadalafil, Canadian Patent No. 2,181,377 (“the ‘377 Patent”). [1] As the earlier three related cases did refer to, but did not benefit from, a Whirlpool analysis, the FCA here decided to review Whirlpool to assess Apotex’s argument. [1]

Both arguments put forth by Apotex were rejected, [2, 3] and the appeal was dismissed with costs. [4]

Background and the Earlier Three Cases

This particular situation began when Apotex brought an application for a notice of compliance (“NOC”) under the Patented Medicines (Notice of Compliance) Regulations (“PM(NOC) Regulations”). [5] Apotex asserted that the ‘784 Patent was invalid on various grounds. [5] The allegations were that the ‘784 Patent, which claimed a monopoly on the use of tadalafil to treat ED, claimed nothing new or inventive in relation to the ‘377 Patent, which had already claimed compounds including tadalafil for use as medicine in humans. [5] This claim relied on the judge-made doctrine prohibiting double patenting. Eli Lilly Canada Inc. (“Eli Lilly”) then brought an application for an order of prohibition to prevent the Minister of Health from issuing an NOC to Apotex. [5]

Concurrently, Mylan Pharmaceuticals ULC (“Mylan”), launched an identical claim against Eli Lilly, also alleging that that ‘784 Patent was invalid for double patenting. [6] Eli Lilly’s application for an order of prohibition was heard at the FC in Eli Lilly Canada Inc v Mylan Pharmaceuticals ULC, 2015 FC 17 [Mylan FC], with judgment and reasons in favour of Eli Lilly. [6] Eli Lilly’s application for prohibition in the Apotex matter was heard and decided similarly in Eli Lilly Canada Inc v Apotex Inc, 2015 FC 875 [Apotex FC] (PCK Reporter summary available Here). [7]

The appeal of Mylan FC resulted in Mylan FCA, where the FCA rejected Mylan’s arguments of double patenting. [8] The argument was wholly dependent on the date at which the comparison between the claims of the ‘377 Patent and ‘784 Patent should be made. [8] The FC rejected the priority date of the ‘784 Patent as the date for comparison of the claims of the two patents. [16] In Apotex FC, Apotex argued that the date of the comparison was the publication date of the ‘784 Patent, while Eli Lilly asserted it was the priority date of the ‘377 Patent. [20] Ultimately, the FC held that the choice of dates did not matter, as the claims of the ‘784 Patent were patentably distinct from the claims of the ‘377 Patent. [26]

Whirlpool Analysis

In Whirlpool, the main issue was whether a patent claiming flexible vanes on a dual action washing machine agitator (“the ‘734 Patent”) was patentably distinct from an earlier patent, which simply claimed vanes on a dual action agitator (“the ‘803 Patent”). [28] It is plain that the party challenging the ‘803 Patent argued for a broad interpretation of the claims, while the patent holder wished for a narrow interpretation. [30] The trial judge was inclined to believe that the ‘803 Patent only referred to rigid vanes. [30] With regard to the law, Binnie J concluded that the issuance of a second patent with claims not patentably distinct from those of the earlier patent is prohibited. [31] The court also affirmed that the essence of the inventiveness in the ‘734 Patent was the combination of flexible vanes with the dual action agitator. [32]

The basis for Apotex’s argument was that the comparison date is the publication date of the later patent. [34] They also claimed that Binnie J would have set the publication date of the later of the two patents as the date for assessing double patenting. [36] However, if Binnie J had intended to decide the issue of the comparison date of the patents in a double patenting suit, he would have done so. [37] The Court also felt that Binnie J’s silence on this matter was intentional, not seeking to settle this concept. [38] Therefore, the FCA did not agree that Whirlpool had decided which date to use in comparing two patents in a double patenting case. [39] Apotex’s argument failed in regard to Whirlpool, and thus also in regard to Mylan FC. [41]

Insufficiency to teach a POSITA

Apotex also argued that the ‘784 Patent was insufficient to teach a POSITA how to proceed from the manufacture of tadalafil to a solvate of tadalafil, particularly a hydrate. [42] It was Apotex’s view that the POSITA would have to experiment beyond the routine aspects and that the results were not guaranteed. [43] The FC accepted this element of experimentation, but nevertheless agreed with Eli Lilly’s expert that this was routine experimentation. [43] As the FC had preferred the evidence provided by Eli Lilly’s expert over Apotex’s expert, and the FCA was not in a position to second guess the FC’s assessment, [46] Apotex’s arguments failed here as well. [47]

Apotex’s application for leave to appeal at the Supreme Court of Canada was dismissed on April 27, 2017.


Many may read a case like this and think of the old idiom “to flog a dead horse.” The legal history of this decision plainly shows that the FCA took a particular point of view and were unwilling to deviate from it. However, it is important to note that a key aspect of this case remains unsettled. That is, what date should be used for the comparison of the claims. The appellant had attempted to argue for a particular date, but the claims in the two patents were patentably distinct and so the choice of comparison dates did not matter. There is little doubt that this concept of comparison dates may arise again in future decisions.