In late January, in two decisions released simultaneously, the Federal Court of Appeal affirmed the broad and factually-suffused nature of the obviousness inquiry.

Context for the Appeals

In Teva Canada Limited v. Pfizer Canada Inc., 2019 FCA 15,[1] and Apotex Inc. v. Pfizer Canada Inc., 2019 FCA 16,[2] the Federal Court of Appeal dismissed two appeals brought by Teva and Apotex. The Court below had rejected Teva’s and Apotex’s allegations that Pfizer’s 668 Patent was obvious and prohibited the Minister of Health from issuing notices of compliance for Teva’s and Apotex’s generic desvenlafaxine products.[3] The 668 Patent covers a crystalline form of a desvenlafaxine salt, Form I desvenlafaxine succinate (“Form I”), a drug used to treat depression.

Both Teva and Apotex argued that Form I – which had been discovered in the course of a salt and crystal screening study – was obvious. In a salt and crystal screening study, a number of salt and crystalline forms of the drug are prepared and characterized to determine which salt and crystalline form has the best properties for drug development. Teva and Apotex argued that the screening study was a routine and obvious part of the development path for the known drug compound.

The Federal Court rejected that argument, holding that it was impossible to predict in advance whether Form I would form as a solid, whether it would be crystalline, or any of its properties. Instead, the skilled person would foresee a difficult and indirect development path.[4]

On appeal, Teva and Apotex alleged a number of errors, including several in common. The Federal Court of Appeal rejected all of them.

Form I’s Properties Were Relevant Context

First, both Teva and Apotex argued that the Federal Court had impermissibly relied on the properties of Form I when determining the inventive concept of the claims of the 668 Patent.[5] In Bristol-Myers Squibb Canada Co. v. Teva Canada Limited, 2017 FCA 76 (“Atazanavir”), the Federal Court of Appeal overturned an inventive concept that focuses on the unobvious properties of the claimed salt .[6]

The appeals court dismissed this argument, holding that the Federal Court’s non-obviousness holding was “grounded in the fact that [Form I] itself is not obvious”, and that references to its properties provided relevant and permissible context for the obviousness inquiry.[7]

Not All Screening Studies Obvious; Each Case Turns on its Particular Facts

Second, both Teva and Apotex argued that the lower Court erred by failing to follow two decisions of the Federal Court of Appeal, Atazanavir and Pfizer Limited v. Ratiopharm Inc., 2010 FCA 204 (“Amlodipine”). In both cases, the patents at issue claimed particularly useful salts discovered using a routine salt screen.[8] In both cases, the claimed salts were held to be obvious. Teva and Apotex argued that Atazanavir and Amlodipine were indistinguishable from this case, and dictated the result.[9]

The court held that while “past cases can provide helpful illustrations” they “cannot be used to force a given conclusion on obviousness based on broad factual similarities to the detriment of otherwise significant differences”.[10] In other words, each obviousness attack turns on its particular facts.