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The Federal Court of Appeal Further Clarifies the Test for Obviousness: That Something is “Worth Trying” Does Not Mean That it was Obvious to Try

March 16, 2021

By Melanie Szweras and Scott MacKendrick

In the recent Federal Court of Appeal decision in Janssen et al. v. The Minister of Health (2021 FCA 45), Justice Locke, writing for the Court, provided further clarity on the test to be applied for a finding that an invention is obvious to try. In particular, Justice Locke elaborates on his previous comments in the Hospira Healthcare Corporation v. Kennedy Trust for Rheumatology Research decision [Hospira] (2020 FCA 30) decision, which some worried could open the door to a more lenient “worth a try” test. 

An appeal on a patent since found invalid

The present case relates to an appeal of a Federal Court decision under the old Patented Medicine (Notice of Compliance) ((PM)NOC) Regulations granting Janssen et al.’s application to prohibit the Minister of Health from granting to Apotex a notice of compliance (NOC). The product at issue was a generic version of abiraterone, marketed by Janssen as ZYTIGA. Apotex argued before the Federal Court that the 422 Patent, which it was required to address since it was on the Patent Register, was invalid for obviousness and patentable subject matter. The 422 Patent concerns the use of therapeutically effective amounts of abiraterone acetate (AA) and prednisone (PN) in the treatment of castration resistant prostate cancer. The same patent was recently invalidated in a separate decision under the current PM(NOC) regime (see Federal Court Invalidates Janssen ZYTIGA Patent) and although arguably moot, this appeal proceeded as it could have an impact on an Apotex section 8 damages claim.

The appeal proceeded regardless of the invalidity finding

On appeal, Apotex argued that the Federal Court required a finding that the person of skill in the art know the results of certain solutions with certainty in order for the claimed combination to be obvious. For example, the Federal Court supported its finding that there was no predictability of an anti-cancer effect when it stated “[a] POS would not know that the two drugs would not, for example, cancel each other’s effectiveness.” Justice Locke was not prepared to infer from this finding that the Federal Court applied a certainty requirement. Apotex also argued that the Federal Court’s acknowledgement that a skilled person would be wary of side effects was also indicative of the Federal Court’s conclusion that the uncertainty about the side effects rendered the combination nonobvious. However, Justice Locke disagreed finding that a skilled person’s concern about side effects “could prompt the Court to consider whether the claimed combination was obvious to try, which it did, but it was not an error to find that the invention was not otherwise obvious.”

The Hospira decision distinguished

Apotex then argued that the Federal Court made an error when applying the obviousness to try test by considering “more or less self-evident that it ought to work” as the overarching requirement, while the other factors, such as extent, nature and amount of effort required, motive to find the solution, and actual course of conduct were mere considerations, relying on Hospira.

However, Justice Locke distinguished Hospira. Justice Locke held that, in the present case, each of the factors were considered by the Federal Court as relevant to the test. In particular, Justice Locke noted that the Federal Court had acknowledged that the skilled person “was motivated to develop secondary hormonal therapies to treat CRPC, and to test AA for that purpose, it was not self-evident that the combination of AA and PN would work, and the trials conducted to achieve the invention were not routine.” He further noted that the Federal Court concluded that “though the combination of AA and PN may have been “worth trying”, it was not obvious to try”. [emphasis added] In finding that this conclusion was open to the Federal Court judge, Justice Locke clarifies that there still is a difference between “worth a try” and “obvious to try”.

Justice Locke concluded by observing that the Federal Court should be “forgiven for its lack of clarity” owing to the “mixed signals” from the Supreme Court of Canada in Apotex Inc. v. Sanofi-Synthelabo Canada Inc., 2008 SCC 61. He underscored that the “more or less self-evident” element in the obviousness analysis is a factor, not a requirement:

I maintain my view that “more or less self-evident that it ought to work” should be treated as a factor in the obviousness to try analysis, and not as a requirement. This appears to be more consistent with what the Supreme Court intended.

A combination vs. aggregation of known elements

Also addressed by the decision is the issue of a combination vs. aggregation of known elements. The Federal Court had held that the claims were directed to patentable subject matter because the claimed combination of AA and PN achieved an anti-cancer effect that was greater than either drug alone. Apotex disagreed with this approach, arguing that the comparison of the combination should have been made with the sum of the two component drugs alone, i.e., that there should be synergy. Justice Locke rejected the need for a comparison to the sum of the two components and instead held that the key consideration should be whether the combination offers something that was not available to the public before. Under this consideration, an aggregation is still problematic because it does not provide something above what was already publicly available. In the present case, there was no dispute that the combination of AA and PN provided improved results over what was previously known.

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Author(s):

Melanie Szweras Melanie Szweras
B.Sc., Ph.D. (Genetics), LL.B.
Partner
416.957.1678  email Melanie Szweras
R. Scott MacKendrick R. Scott MacKendrick
B.A.Sc. (Chem. Eng.), LL.B.
Partner
416.957.1675  email R. Scott MacKendrick