In a pair of decisions, the Federal Court granted orders prohibiting Apotex and Teva from marketing their generic o-desmethyl-venlafaxine (ODV) succinate products (Pfizer's Pristiq) until the expiration of Patent 2,436,668 (the 668 Patent) (for further details please see "Pfizer obtains prohibition orders for polymorphic form patent"). On 25 January 2019 the Federal Court of Appeal dismissed both Apotex's and Teva's appeals.(1)
The 668 Patent relates to a novel crystal form of a particular salt of ODV: Form I ODV succinate. Obviousness was the only issue in Teva's appeal. Obviousness and anticipation were at issue in Apotex's appeal.
Application judge did not err in applying test for obviousness Both Apotex and Teva argued that the application judge had misapplied the test for obviousness. The Federal Court of Appeal disagreed, observing that the judge had used the four-step inquiry provided by the Supreme Court in Apotex v Sanofi Synthelabo (2008 SCC 61). In applying the test, the application judge had addressed both obvious to try and recent guidance from the Federal Court of Appeal in Bristol-Myers Squibb Canada v Teva (2017 FCA 76) (Atazanavir).
In view of this conclusion, the Federal Court of Appeal emphasised that "absent any palpable and overriding error by the Federal Court Judge, this Court ought not to interfere with his findings of fact or mixed fact and law". The application judge is entitled to deference in weighing the evidence.
Application judge did not err in distinguishing recent court decisions Both Apotex and Teva argued that the application judge had erred in declining to follow Atazanavir and Pfizer v Ratiopharm (2010 FCA 204) (Amlodipine). Apotex elaborated, asserting that the present case involved salts, not crystal formation, and should be interpreted consistently with Atazanavir, Amlodipine and other salt cases. The Federal Court of Appeal disagreed, stating that the present case was distinguishable on the basis that:
- the inventive concept was a novel crystalline form (not a salt);
- there was no motivation to prepare ODV succinate; and
- "it was not predictable whether Form I ODV succinate could be prepared at all".
Moreover, Apotex's own witness "confirmed that crystal structures are not predictable".
Application judge did not err in discussing properties of novel crystal form The parties agreed that "the inventive concept or the solution taught by the 668 Patent [was] the novel crystal Form I ODV succinate" and did not include properties of the compound. Both Apotex and Teva argued that the trial judge had improperly relied on the fact that properties of Form I ODV succinate were unpredictable in finding the invention non-obvious.
Although the application judge had discussed properties of Form I ODV succinate, the unpredictability of these properties was not the basis for his conclusion of non-obviousness:
Rather, the Federal Court Judge relied on evidence that demonstrated that a skilled person could not have known or predicted that the Form I ODV succinate – i.e., the crystal form itself – could be made or even existed.
Moreover, the Sanofi approach is a "flexible, contextual, expansive and fact driven inquiry" permitting the application judge to discuss properties.
Application judge did not err in considering course of conduct Apotex and Teva argued that the application judge had erred in considering several aspects of the inventors' course of conduct. The Federal Court of Appeal disagreed.
First, Teva argued that by Pfizer's difficulties with ODV fumarate – a different salt of ODV – would have been unknown to the skilled person and thus should not have been factored into the analysis of the amount of effort required to obtain the invention. This argument was rejected, as Sanofi "expressly permits consideration of the course of conduct of those involved in the claimed invention including the inventor and his or her team".
Second, Apotex argued that Wyeth's (Pfizer's predecessor) failed efforts in other directions – including work relating to ODV fumarate and an ODV prodrug – were irrelevant to the invention story. The Federal Court of Appeal disagreed, holding that, as per Sanofi, "time, money and effort… expended in research looking for the result the invention ultimately provided before the inventor turned or was instructed to turn to search for the invention" may be considered as part of the inventors' course of conduct.
Third, Apotex argued that work conducted after Wyeth had prepared and identified Form I ODV succinate – considered by the application judge – was irrelevant. The Federal Court of Appeal concluded that the application judge did not err in considering these efforts. This extensive research (a polymorph screen conducted by a contractor) was a continuation of the patentee's work and "required in order to conclude that Form I ODV succinate was the most stable hydrated form". Prior to the contractor's work, the patentee did not know what it had; "the new crystal form still needed to be characterized."
Evidence alleged to be hearsay was not determinative Teva argued that the evidence that individuals at Wyeth had been sceptical that the difficulties with ODV succinate could be overcome by another salt (eg, ODV succinate) was hearsay. The Federal Court of Appeal determined that this evidence was "neither determinative nor decisive". Even if this evidence had been excluded, the application judge's other findings supported his conclusion of non-obviousness.
To establish anticipation, Apotex relied on expert evidence addressing obviousness, which had been rejected by the application judge. The Federal Court of Appeal found that, even if accepted, Apotex's evidence would not have established anticipation. The application judge considered "the only piece of the prior art that could possibly have disclosed the invention" and found that it "did not disclose the Form I ODV succinate".
If Apotex and Teva wish to appeal the decisions, they must seek and obtain leave from the Supreme Court of Canada.
Endnotes
(1) Teva v Pfizer (2019 FCA 15) and Apotex v Pfizer (2019 FCA 16).
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