The Federal Court of Appeal (“FCA”) upheld the validity of Canadian Patent 2,436,668 (“668 Patent”) which covers Form I ODV succinate (marketed as PRISTIQ) in two separate appeals by Apotex Inc. (“Apotex”) and Teva Canada Ltd (“Teva”), finding that the claims were novel and inventive.
The FCA began be reiterating key points of the obviousness analysis:
- The Sanofi test is flexible and expansive and can include consideration of the invention story as a whole;
- The “obvious to try” test is only one part of the obviousness analysis and does not displace other tests, including the test set out in Beloit Canada Ltd. v. Valmet Oy, (1986), 64 N.R. 287, 8 C.P.R. (3d) 289 (F.C.A.), i.e., whether the skilled person would have come “directly and without difficulty” to the solution taught by the patent;
From this framework, the FCA found that the claims of the 668 Patent were inventive, focusing on the Federal Court’s findings that:
- None of the crystal forms of ODV succinate had ever been made, disclosed, or characterized;
- it was impossible to predict whether or how ODV succinate could be made;
- there was a lack motivation to form ODV succinate because past experiments with ODV fumerate (another salt of ODV) had failed (it had poor bioavailability); and
- many experiments were required to produce the crystal form.
In both appeals, the FCA rejected arguments that the claims were “obvious to try” in light of Bristol-Myers Squibb Canada Co. v. Teva Canada Limited, 2017 FCA 76 (Atazanavir) and Pfizer Limited v. Ratiopharm Inc., 2010 FCA 204 (Amlodipine), which cases related to salts. The FCA noted that there was evidence in Atazanavir and Amlodipine that the salts in issue had already been shown to offer stability advantages and improved pharmaceutical properties. By contrast, salts of ODV succinate would have not have been expected to work because the ODV fumerate salt had not worked.
In the Apotex appeal, the FCA rejected Apotex’s argument that experiments unrelated to the salt screens for ODV succinate, such as prior experiments with pro-drugs and with ODV fumerate should be excluded from consideration because they were efforts “in other directions”. The FCA disagreed and confirmed that it the entirety of the inventors’ course of conduct could be considered including other directions and approaches taken to solving the problem.
Similarly, the FCA also rejected Apotex’s argument that tests that occurred after the ODV succinate crystal was discovered should not be considered. The FCA found that the crystal form needed to be characterized and the stability of other forms analyzed in order to confirm that the identified crystal was the most stable hydrated form and that these experiments were relevant considerations in the obviousness analysis.
Apotex’s appeal also raised issues of anticipation that were not present in Teva’s appeal. At first instance, Apotex did not lead direct evidence of anticipation but addressed it in its memorandum, relying on evidence from its experts on obviousness. The Federal Court rejected this approach because neither expert was instructed on the law of anticipation, the expert evidence related to obviousness, and a party cannot use information filed in relation to one issue to attack a different issue.
The FCA confirmed that obviousness and anticipation are separate inquiries, but did not directly address the Federal Court’s holding on whether expert evidence on the issue of obviousness could be used to support an anticipation analysis. Instead, it found that Apotex’s evidence was insufficient to prove anticipation so it was irrelevant whether the Federal Court considered it.
*Special thanks to Jamie Parker, an articling student, for his help on this post.