Living Separate and Apart is Never Easy: Obviousness and Inventiveness in Pharmaceutical Litigation

Ron A. Bouchard is an Associate Professor in the Faculties of Medicine & Dentistry and Law, University of Alberta. 

The Canadian Patent Act defines an invention as any “new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter.” An invention must meet three basic requirements in order to be patentable; the subject matter defined in the claims must be new, useful and non-obvious.

The first requirement is met where the subject matter of the patent has not yet been disclosed to the public. The second is met where the subject matter provides sufficient utility or benefit to the public and achieves the purpose for which it came into being. The third is met where the subject matter constitutes an “inventive step” or manifests sufficient “inventive ingenuity” over the prior art to warrant the traditional patent bargain. Where an inventive step is lacking, a patent is not granted or, if granted, can be later ruled invalid on the grounds that it is “obvious” in light of the prior art, provided that the person skilled in the art would have been led directly and without difficulty to the solution taught by the patent. When the claims at issue are deemed to be obvious or anticipated (for lack of novelty), they are struck down and can no longer be used to prohibit competitors from using the invention.

Under the terms of the Act, the lens through which the court must gaze when deciding the issue of obviousness is that of a Person Having Ordinary Skills in the Art, also referred to as the PHOSITA. When assessing the issue of obviousness courts are charged with undertaking a determination of whether the impugned invention represents an inventive step over the prior art, including previously disclosed inventions.

One problem that frequently comes up in the obviousness analysis is whether or not experimental research or testing leading to crystallization of the impugned invention constitutes an inventive step from the perspective of the PHOSITA. The issue of “testing” is thus shorthand for whatever scientific experimentation and research was conducted prior to crystallization of the invention. The issue of testing is significant in the context of pharmaceutical inventions because like all biomedical inventions they typically come about as a result of cumulative incremental advances over the prior art; that is, they do not come into being in vacuo.

There is considerable “push-pull” between inventiveness and obviousness in determining the validity of a patent. While in one sense there is a zero sum game between the two concepts insofar as the final decision of the court is concerned (the invention is either valid or invalid), in a more subtle sense, there is a broad spectrum of potential research and testing leading up to crystallization of the invention that cannot be seen in a binary fashion and which only the PHOSITA is positioned to judge.

For example, assume it was well known to an industrial drug development PHOSITA that ingestion of one of either two known methylxanthine compounds, theophylline or theobromine, yields a mild stimulant effect in humans by raising the levels of cyclic AMP and antagonizing endogenous adenosine. The patentee conducts an array of simple tests in the lab using well known methods and equipment, and finds that a small and easy to effect change in the ring structure of either compound produces yet another methylxanthine compound, caffeine, which has a substantially larger stimulant effect via the same two biochemical pathways as theophylline and theobromine. Does the discovery of the stimulant effects of caffeine amount to the exercise of sufficient inventive ingenuity to constitute a patentable invention, or is it obvious in light of the known existence, chemical structure, stimulant effects and mechanism of action of the parent compounds? One could ask the same question under circumstances where all three methylxanthines were known in the art and later testing showed that caffeine had the same or similar stimulant effects as previously documented for theophylline and theobromine. The potential combinations are endless.


On the one hand, it might be said that only very minor or “routine” (e.g., non-inventive) testing was needed in order to simply confirm caffeine had properties similar to those of other known methylxanthines. On the other hand, it might be said that there is sufficient uncertainty involved in any testing that the mere act of undertaking it is an expression of sufficient inventive ingenuity to warrant a patent. Thus, obviousness and inventiveness represent divergent positions on the continuum of potential inventive activity undertaken by patentees as well as that contemplated by the PHOSITA in the post-hoc obviousness analysis. It is the overlapping grey zone between the two poles that has presented the greatest challenge to courts grappling with the issue.

While obviousness and inventiveness are opposite ends of the spectrum of activity leading up to invention, the roof under which they co-inhabit, however uncomfortably, is that of human agency. Notwithstanding the PHOSITA represents at once the metric for the obviousness analysis undertaken by the courts, the class of persons most likely to be actual inventors in reality, and the societal medium through which all pharmaceutical inventions emanate and are vetted, rejected and put into practice, Canadian patent jurisprudence and legal commentary nevertheless stipulates that for an invention to be obvious, no “experimenting or serious thought, or research, whether the research be in the laboratory or amongst literature” can be conducted in the lead-up to invention.

Judicial reasoning underpinning this approach hinges on the current legal fiction of the PHOSITA, who is said to possess not even a “mere scintilla” of inventiveness or creativity. This is true independent of whether the obviousness analysis is couched as an express injunction against testing or the “worth a try” approach to testing or whether the PHOSITA “would have” versus “could have” arrived at the impugned invention. The approach taken by Canadian courts on the issue is highly binary in nature, which contrasts sharply with the spectrum of inventive activity engaged in by both actual patentees or more generally by persons skilled in the art of pharmaceutical research and development.

In order to gain a better understanding of the issue, a social sciences construction of the normative practices of the pharmaceutical PHOSITA was undertaken. This involved evaluating the scientific norms of industrial pharmaceutical research and development, with particular focus on the identity and inventive capacity of the pharmaceutical PHOSITA. Two analytical methods were employed in the analysis: the tacit and focal knowledgebase framework of Polanyi and actor-network theory (ANT) as described by Latour.

Both methods yielded a nuanced and complex picture of the normative PHOSITA, who was seen to be highly creative and inventive. The normative PHOSITA was viewed to be comfortable with, indeed strongly adapted to, working under conditions of profound uncertainty and ambiguity, with one eye focused firmly on the commercial, regulatory, legal and political implications of their day-to-day activities. Moreover, from an ANT perspective, pharmaceutical inventions are not the result of individual scientists working alone in a laboratory but rather are the product of numerous actors working in concert with common (yet diverse) interests in the commercialization of pharmaceutical products.

Based on these observations, the normative PHOSITA is more legitimately described using terminology that incorporates a combination of indeterminate and determinate language rather than the binary language currently used to describe both the PHOSITA and the role thereof in the obviousness analysis. As described, the social sciences analysis is consistent with a flexible approach to obviousness, which would allow contemplation of experimental testing in the post-hoc analysis without automatically vitiating a finding of obviousness. Finally, even assuming a modern deterministic approach to obviousness, it was demonstrated that certain elements of the “no testing” approach, in particular the “worth a try” formulation articulated by Justice Lederman in Bayer, is unworkable in light of current best-practices in pharmaceutical drug development.

The legal nexus between the normative PHOSITA and the test for obviousness was provided by a “purposive construction” of obviousness in accordance with the Supreme Court of Canada’s leading patent jurisprudence. A purposive construction emphasizes the essence of an invention, including the steps taken to achieve it, rather than binary notions of testing/no testing, scintilla/no scintilla of inventiveness, whether the PHOSITA viewed the invention as not/worth a try, or whether the PHOSITA would have/could have arrived at the invention. This binary can also be extended to routine/not routine testing in so far as taking that approach is antithetical to recognizing the potential spectrum of inventive and non-inventive activity leading up to invention. Instead, a purposive approach to obviousness focuses on whether the testing leading up to the invention was, in the mind of the normative PHOSITA casting their mind back to the claim date in light of all the prior art, inventive or not and whether in this light the PHOSITA would have come “directly and without difficulty to the invention.” A purposive construction views the concepts of inventiveness and obviousness as tied together in a fluid and graded manner through the contextual and evidence-based skills of the PHOSITA and thus is at once objective and evidence-based, yet contextual.

Finally, it was argued that the purposive approach to obviousness is conducive to domestic and international patent policy which facilitates rather than impedes strong innovation. This is particularly relevant to the North American pharmaceutical industry due to peculiarities in the substance and procedure of the linkage regime governing drug approval and patenting and because the industry has become plagued by non-inventive line extension patents to the detriment of the public. This has resulted not only in less competition between brand and generic firms but also reduced access by the public to essential drugs. The importance of the obviousness test to innovation is underscored by Canadian and American appellate jurisprudence to the effect that the nonobvious requirement is the primary mechanism by which non-inventive patents are weeded out of the system and the public protected from undue patent monopolies.

Full Cite: Ron A. Bouchard. Living separate and apart is never easy: Inventive capacity of the PHOSITA as the tie that binds obviousness and inventiveness. University of Ottawa Law & Technology Journal. 4(1). 1-57. 2007