Thursday, February 20, 2020

Obvious to Try Does Not Require That it Is Obvious That What Is Being Tested Will Work

Hospira Healthcare Corporation v. Kennedy Trust for Rheumatology Research 2020 FCA 30 Locke JA: Rivoalen, Nadon JJA var’g 2018 FC 259 Phelan J
            2,261,630 / infliximab / INFLECTRA

There is some confusion in the obvious-to-try test as discussed in Sanofi 2008 SCC 61. At one point the SCC stated that

[65] I am of the opinion that the “obvious to try” test will work only where it is very plain or, to use the words of Jacob L.J., more or less self-evident that what is being tested ought to work.

This lends itself to the view that it must be self-evident, prior to any experimentation, that the claimed invention will solve the problem at hand. But there is a second understanding of the obvious-to-try test that emerges from the very next paragraph, where the SCC went on to say (my emphasis):

[66] For a finding that an invention was “obvious to try”, there must be evidence to convince a judge on a balance of probabilities that it was more or less self-evident to try to obtain the invention. Mere possibility that something might turn up is not enough.

This implies that it must be more or less self-evident to try, not more or less self-evident that what is being tried will work.

In my view, the latter interpretation is preferable. As the SCC noted at [68], the obvious to try test is appropriate “[i]n areas of endeavour where advances are often won by experimentation.” In such fields, a test requiring that it is very plain, prior to any experimentation, that the invention would work, would mean almost nothing would be obvious. On the second interpretation of Sanofi, if something is obvious to try, and when tried, it works without difficulty, there is no inventive ingenuity involved in arriving at the invention, even though the result could not have been predicted in advance. So, if a routine salt screen discloses that the maleate salt of a new pharmaceutical has good manufacturability, that might not support a patent to the maleate, even though it could not have been predicted in advance that the maleate would be better than any other pharmaceutically acceptable salt.

As I have discussed in previous posts (here and generally here), the Federal Court has quite consistently applied the second approach to the obvious-to-try test, under which an invention might be considered obvious even though a successful outcome could not have been predicted in advance.

In this case, Phelan J appeared at some points to apply the first approach, saying that “Although the POSITA may have had “good reason” to pursue the combination of anti-TNF-α and MTX, it was not self-evident that this combination would work to solve the problem identified in the prior art” [226] (and see similarly 228].) The FCA disapproved of this statement, with Locke JA saying at [94]:

[T]his factor is not determinative. The other factors also required consideration. In my view, the Judge’s analysis of the second factor (concerning the extent, nature and amount of effort required to achieve the invention) was inadequate.

This means that the mere fact that a successful outcome could not have been predicted in advance does not mean that the invention is not obvious under the obvious-to-try test. This is a welcome affirmation from the FCA that the second approach to the obvious-to-try test that I have outlined above is indeed preferable.

However, the FCA went on to say (my emphasis) that:

[95] The determinative test on this issue is whether it was more or less self-evident to try to obtain the invention, including co-administration of an anti-TNF-α antibody and MTX to treat RA in MTX IRs.

This implies that if an invention was obvious to try, it will necessarily be obvious under the obvious to try test. The statement that this is the "definitive test" is difficult to reconcile with the SCC’s statement in Sanofi at [64] that ”the ‘obvious to try’ test must be approached cautiously. It is only one factor to assist in the obviousness inquiry.” Similarly, the SCC remarked that "obvious to try” is “not a mandatory test,” but rather “one factor of a number that should be considered, having regard to the context and the nature of the invention” [62]. So, I would suggest that if a particular avenue is obvious to try, and it eventually succeeds, but only after prolonged and difficult experimentation, it may well be inventive even though it was obvious to try. [Update: On re-reading, I think that Locke JA meant only that this was the determinative test on the facts of this case, not that it is the determinative test generally.] 

On the facts, I would note that while at places Phelan J did indicate that the invention was not obvious to try simply because it was not self-evident that it would succeed, other statements can be taken to imply it was not obvious even to try (see esp [223]).

Both Phelan J [24] and Locke JA [15] remarked on the vast array of issues raised by Hospira, to the extent that Locke JA stated that “it will not be practical to address each one specifically” [15]. I can only suppose that as a consequence, the submissions weren’t as fully prepared as they would have been if the arguments had been more carefully focused, and I can’t help but feel that this is reflected in the reasons.


  1. At the outset, I would like to say that I really enjoy reading your articles and almost always agree with them. However, I don’t think that Sanofi makes the distinction you are suggesting. You are hanging your hat on the first sentence of paragraph 66, but the rest of the decision must also be considered.
    For instance, paragraph 69:
    [69] If an “obvious to try” test is warranted, the following factors should be taken into consideration at the fourth step of the obviousness inquiry. As with anticipation, this list is not exhaustive. The factors will apply in accordance with the evidence in each case.
    1. Is it more or less self-evident that what is being tried ought to work?
    And then the ratio decidendi expressed in paragraphs 83 to 85:
    [83] The following factors are therefore relevant at this fourth step of the obviousness inquiry:
    (1) Is It More or Less Self-Evident That What Is Being Tried Ought to Work?...
    [85] … However, a possibility of finding the invention is not enough. The invention must be self-evident from the prior art and common general knowledge in order to satisfy the “obvious to try” test…

    1. Thanks for your comment. I agree that Sanofi itself does not make that distinction, at least not clearly; on the text of Sanofi alone, either interpretation is possible. I suggest that interpreting a statement of the SCC (or any court), should be approached in much the same way as interpreting a statute. Text is important, but context and purpose are also important, especially when the text is ambiguous (though even clear text can be overridden when the context and purpose point sufficiently clearly in a different direction): see Canada Trustco 2005 SCC 54 at [10]; [1993] 2 SCR 451 esp at 477. So, the context — the prior leading cases, such as Johns-Manville — and the purpose — to ensure that patents are granted only for those inventions requiring the lure of a patent — must both be taken into account in interpreting Sanofi on the obvious to try test. I would suggest that both context and purpose point strongly to the second interpretation, while the text of Sanofi is ambiguous, or at the very least, is reasonably capable of bearing that second interpretation.

  2. Thank you for the blog, Norman. I'm a regular reader and benefit greatly from your insights. Is there a missing perspective here? As per the Beloit standard of obviousness ("scintilla of...", affirmed in Sanofi), I strain my mind to think of scenarios where something is obvious to try but not obvious to work. The clear example is a finite, limited set of possibilities where it is obvious that at least one of the set will work and sub-Beloit standard of inventiveness is needed to identify the claimed subject matter from the set. However, this example is consistent with both paragraphs 65 and 66 of Sanofi, i.e. to satisfy Beloit there must be at least a latent "obvious to work" in the schema of the "try" for the try to be obvious. This is also appears more-or-less consistent with the US standard of "reasonable expectation of success". I admit, I consulted MOPOP 18.02.03 "Obvious to try considerations" when I read this.