Teva v AstraZeneca - UK Patents Court’s Recent Holding On Common General Knowledge For Obviousness Inquiry

On September 2, 2014, Justice Sales, sitting in the UK Patents Court, released his decision in Teva v AstraZeneca, [2014] EWHC 2873 (Pat), holding that AstraZeneca’s EP (UK) patent (the Patent) covering the use of a combination of formoterol and budesonide (AstraZeneca’s SYMBICORT) in a single inhaler for regular maintenance of asthma and relief of acute asthma was invalid on the ground of obviousness. In this decision, Justice Sales called for an adaptation and modernization of the concept of common general knowledge (CGK) to bring it in line with the procedures for dissemination of scientific knowledge in the age of the Internet and digital databases of journal articles. This could be relevant in Canada since Canadian courts have adopted the UK’s four-stage approach to assessing obviousness, with the second stage being to identify the “relevant common general knowledge” of a notional person skilled in the art (the skilled person) (see Apotex Inc v Sanofi-Synthelabo Canada Inc, 2008 SCC 61). The issue before Justice Sales was whether the combined maintenance and relief treatment in a single inhaler was novel and not obvious at the priority date of the Patent. While the Patent was found to be novel, it failed for being obvious. A key issue was the parties’ dispute over what constituted the relevant CGK of the skilled person (identified as “a clinician with a specialist interest in the management and treatment of asthma”). Prior approaches to CGK The House of Lords in General Tire v Firestone, [1972] RPC 457, held that a piece of particular knowledge in a scientific paper only becomes general knowledge when it is "generally known and accepted without question by the bulk of those who are engaged in the particular art; in other words, when it becomes part of their common stock of knowledge relating to the art". Subsequently, Laddie J., in Raychem Corp’s Patents, [1997] EWHC 372 (Pat), explained that:

The common general knowledge is the technical background of the notional man in the art against which the prior art must be considered. This is not limited to material he has memorized and has at the front of his mind. It includes all that material in the field he is working in which he knows exists, which he would refer to as a matter of course if he cannot remember it and which he understands is generally regarded as sufficiently reliable to use as a foundation for further work or to help understand the pleaded prior art. This does not mean that everything on the shelf which is capable of being referred to without difficulty is common general knowledge nor does it mean that every word in a common text book is either. In the case of standard textbooks, it is likely that all or most of the main text will be common general knowledge. In many cases common general knowledge will include or be reflected in readily available trade literature which a man in the art would be expected to have at his elbow and regard as basic reliable information.

The approach to CGK in Teva v AstraZeneca In this case, Justice Sales identified three classes of CGK that could be relevant to the case at issue. First, conventional CGK, being statements in standard reference texts and in guidelines issued by panels of experts and a few leading journal articles published in, eg, The Lancet and New England Journal of Medicine. Second, “primary articles”, being other academic articles that were sufficiently prominent in the main academic journals in the field. Third, “secondary articles”, being journal articles that were not published in leading journals in the field and would not have been likely to have been read by skilled persons in the ordinary course of keeping themselves up to date; however, these materials would have been quickly identified by any person conducting a literature search and review. The third category of CGK appears to fall outside of the traditional definition of CGK. Justice Sales explained that the inclusion of this category in the CGK was necessary to keep up to date with the procedures for dissemination of scientific knowledge in the age of the Internet and digital databases of journal articles. Justice Sales also considered “tertiary articles”, which were journal articles that were published or available after the priority date (ie, not part of the CGK) but were indicative of what the skilled person would have thought in light of the available literature as of the priority date. He stressed the importance of exercising caution in assessing such submissions. Obviousness In his draft judgment, Justice Sales held that in light of his findings of the state of the CGK at the priority date, the Patent was obvious. Subsequently, having heard further arguments that Teva’s obviousness case was based on one particular piece of prior art read in light of the CGK, Justice Sales amended his draft judgment so as to bring that piece of prior art back into the picture. However, he still found that the Patent was obvious. Summary by: Junyi Chen