The skilled person - more knowledgeable than ever before

The concept of common general knowledge (CGK) occupies a more prominent position in the UK’s inventive step regime than it does in the European Patent Office's (EPO) problem-and-solution approach or the classic U.S. analysis in Graham v John Deere. The EPO and US approaches start by considering the prior art whereas the UK courts, following Pozzoli v BDMO, start with the skilled person and his or her CGK, putting that background knowledge in the spotlight and at the forefront of the mind of the skilled person for the later stages of the analysis.

The skilled person, memorably described by Jacob LJ in
Rockwater v Technip as "a nerd".
The courts have therefore tended to be careful in expanding out the scope of CGK, and for good reason: if the CGK is deemed to encompass more information, then the skilled person inherently knows correspondingly more about the background technology. Such a know-it-all will tend to regard fewer inventions as being inventive. So changing the CGK analysis inevitably changes the test for inventive step.

All of this helps explain why the IPKat is so exercised by yesterday’s decision in Teva UK Limited & another v AstraZeneca AB [2014] EWHC 2873 (Pat), decided by Mr Justice Sales in the Patents Court. The judge has held that the guidance from the traditional authorities on common general knowledge 
needs to be adapted and kept appropriately up to date for the procedures for dissemination of scientific knowledge in the age of the internet and digital databases of journal articles”. 
Such an approach, he held, should include academic articles which “would not have been likely to have been read by the notional skilled person in the ordinary course of keeping himself up to date” but “would have been quickly identified by any person conducting a literature search and review into [the state of the art]”. As it happens, the articles which fell into the CGK under this updated analysis were also held not to have affected the outcome in any sense. Nevertheless, this Kat disagrees with the principles behind the judge’s analysis and wonders what readers make of it.

The case is not without other interest, and the IPKat may return to it in future posts: in particular the judgment contains an intriguing postscript detailing why a critical section had to be rewritten after it was circulated in draft form to the parties and was criticised by the patentee.

AstraZeneca's product under the patent - Symbicort
Without getting too immersed in the details of the invention, all of which are explained with crystal clarity by Mr Justice Sales, the patent was for a second or subsequent medical use involving a known combination of drugs for treating asthma (formoterol and budesonide, since you ask). Asthma treatment typically has two parts: the patient takes one drug or drug combination via inhaler morning and night to keep the chronic condition in check (“maintenance treatment”), and then supplements this as necessary with another fast-acting drug to deal with acute asthma attacks that nevertheless occur (“relief treatment”).

The combination of formoterol and budesonide was known from the closest prior art document, which taught the use of this combination for maintenance treatment, but not for relief treatment. The claims require using this same combination as needed for relief from asthma attacks and also for maintenance treatment. The case turned on whether the CGK made it obvious to use the same combination for both aspects of asthma treatment, and following the Pozzoli approach, the judge had to decide on the content of the CGK.

I.                The conventional CGK
We can move quickly past the first two categories of CGK as they are uncontroversial. First there were classic items of CGK: statements in standard reference texts and in the guidelines on asthma care issued by the British Thoracic Society and US National Institutes of Health. Secondly, there were a few leading journal articles from The Lancet and the New England Journal of Medicine which addressed the treatment of asthma using combinations of β2-agonists (such as formoterol) and steroids (such as budesonide). Neither side disputed that these articles represented CGK.
The standard reference work, a piece of good,
old-fashioned, CGK

II.             The next level of CGK
Then there was a third category of articles, for which the IPKat wishes to slow down and appeal for witnesses, without stopping on this occasion. The judge called these the “primary articles”, and they were described as academic articles which “were sufficiently prominent in the main academic journals in the field as to constitute part of the relevant CGK”. This is more of a conclusion than an explanation, but it’s the only reason given for the primary articles being part of the CGK.

The IPKat is unsure whether these primary articles provided the only basis for certain findings, most notably the finding that formoterol had a rapid onset of activity. The conventional CGK is not clearly mentioned as a source for that information, and without it, the skilled person might have struggled to arrive at the invention. It is also not clear on first reading whether AstraZeneca fought the inclusion of these articles in the CGK, and if so, what the competing arguments were or why Teva’s arguments were preferred.

Rather than weighing in on issues that may not be controversial or even relevant, the IPKat wonders if anyone involved in the case can clarify whether the inclusion of the primary articles changed the outcome of the case, and if so, whether their inclusion was contested.

III.          The controversial CGK
Finally, arriving at the documents whose inclusion is controversial (to this Kat at least), these were referred to by the judge as the “secondary articles”. They were described at [58] as a range of journal articles:

“which were not in leading journals in the field of respiratory medicine, and would not have been likely to have been read by the notional skilled person in the ordinary course of keeping himself up to date. On the other hand, these materials would have been quickly identified by any person conducting a literature search and review into the use of formoterol and ICS in relation to the treatment of asthma.”

The judge expanded at [60] on the reason for their inclusion:

The authorities [unfortunately, none are cited; this is left as a general appeal to unstated authorities] indicate that CGK includes not just information directly in the mind of the notional skilled person, but such information as he would be able to locate by reference to well-known textbooks. This guidance needs to be adapted and kept appropriately up to date for the procedures for dissemination of scientific knowledge in the age of the internet and digital databases of journal articles. Searches of such databases are part and parcel of the routine sharing of information in the scientific community and are an ordinary research technique. In my view, if there is a sufficient basis (as here) in the background CGK relating to a particular issue to make it obvious to the unimaginative and uninventive skilled person that there is likely to be -- not merely a speculative possibility that there may be -- relevant published material bearing directly on that issue which would be identified by such a search, the relevant CGK will include material that would readily be identified by such a search.

This does not sit comfortably with this Kat’s view of what the CGK should be based on. It’s all very well to say that times have changed and that information is shared differently in the digital age, but the nature of content published in different categories of source material (textbooks v seminal articles in the field v articles published in lesser journals that are not generally known to all practitioners) has surely not changed so much over time.

Indeed, the crux of whether or not a document represents the CGK has always (to this Kat’s mind) been less a function of where the information is located, and more a factual question of whether the information is of such a nature that it forms part of the skilled person’s toolkit – the basic knowledge against which such a person would inevitably evaluate any teaching, whether such knowledge is normally carried around in one’s head or instead is delegated to reference material which the skilled person can readily look up.

The judge’s approach suggests a different category of knowledge, at least as this Kat reads it, suggesting that when the skilled person reads a document, and that document makes it clear that there is more to learn, then he or she will be prompted to track down such additional information in the literature. As long as it is readily identifiable in that search, it appears that this should form part of the CGK.

The traditional approach
More fundamentally, the approach in Teva is stated as an updating of traditional guidance from the authorities, but one can question whether those authorities are characterised correctly. Admittedly, the IPKat does not know what authorities the judge was referring to when he said 
“The authorities indicate that CGK includes ... such information as [the skilled person] would be able to locate by reference to well-known textbooks”.  
It is this approach, the ability to locate information, that is built on and expanded for the digital age to encompass articles one can find in databases and which one knows or suspects must exist.

But rewind a little and consider if the CGK did in fact always include whatever you would be able to locate in a textbook? That question was addressed by Laddie J in Raychem Corp’s Patents [1997] EWHC 372 (Pat), where he took a more nuanced view:

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.

If that statement of the law is correct, then it was never enough that information could be found in a text book. It also had to be material that the skilled person (a) knew existed, (b) would refer to as a matter of course, and (c) understood as being generally regarded as sufficiently reliable. In expanding CGK out as he has done, Mr Justice Sales’s test omits any requirement that the information should be something that the skilled person would refer to as a matter of course, and that he or she would understand as being generally regarded as a reliable foundation. Most research papers in journals, especially those journals that are not the flagship publications in a given field, fall far short of that level of authority and are nowhere near as reliable as a textbook.

Another criticism that can be levelled at this new approach is that, while scientific papers may be distributed and consulted differently than in the past, the nature of what they carry has not changed much. Indeed one could argue that the skilled person in any given field nowadays is probably less aware of the content of the average paper in his or her field than would have been the case decades ago (when the quantity of reading material was so much easier to keep up with). Scientific papers were considered specifically by the House of Lords in  General Tire v Firestone [1972] RPC 457, Sachs LJ quoting with approval from British Acoustic Films (53 RPC 221 at 250) where Luxmoore J said:

A piece of particular knowledge as disclosed in a scientific paper does not become common general knowledge merely because it is widely read, and still less because it is widely circulated. Such a piece of knowledge 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. [Sachs LJ commented that the phrase “accepted without question” was putting it a little high, and perhaps might be replaced by “generally regarded as a good basis for further action"]

Never one to pass by a pithy summation, Lord Justice Jacob also relied on the same passage in more recent times when giving his take on common general knowledge in Rockwater v Technip [2004] EWCA Civ381:, Having cheerily described the skilled person as "a nerd ... but not a complete android" (language which drew frosty disapproval from Lord Justice Pill in his concurring decision), Sir Robin then turned to the CGK:

For brevity I do not quote [the passage from General Tire] in full – Luxmoore J's happy phrase "common stock of knowledge" conveys the flavour of what this notional man knows.

The common thread from these authorities, which appears to be missing from the approach taken in Teva v AstraZeneca, is the requirement that knowledge needs to be generally known and accepted as uncontroversial, to form part of the common stock, before it can be regarded as part of the CGK. Information, even correct and relevant information, falls short of being CGK as long as it remains obscure and not widely known.

The documents which made it into the CGK under Mr Justice Sales’s test in Teva were, by contrast, unknown to the skilled person until he or she read something that suggested their existence. Their character was also far removed, it is suggested, from the types of information usually accepted as part of the common stock: they were papers describing various recent studies with, by and large, only tentative conclusions from their authors, those conclusions being in some cases mutually contradictory. As noted at the beginning, the judge found that whether or not these documents made it into the CGK did not affect the overall outcome. Nevertheless, the question arises whether the approach is correct for future cases.

So readers, what do you think? Is the test for inclusion of a scientific paper in the CGK ripe for an update? Are the authorities mentioned above by the IPKat outdated in the digital age? Should CGK depend on widespread acceptance, or should it turn on ease of access to a publication using modern tools?

Feline asthma here
CGK airport here
C., G. K. (ok, it's a stretch) wrote the Father Brown stories which you can read for free here
The skilled person - more knowledgeable than ever before The skilled person - more knowledgeable than ever before Reviewed by David Brophy on Thursday, September 04, 2014 Rating: 5


  1. I've not given this decision any deep consideration, but at first blush it goes against the grain for me.

    The EPO already appears in many cases willing to combine documents from dispirate technical fields - I've had one case where a component from a car's windscreen washer tank was used in combination to render obvious an invention relating to a subsea hydrocarbon extraction facility. For me, the argument seems entirely legitimate that using a component from a dispirate technical field (or a similar component) can itself be an inventive act.

    This "everything is available on the internet these days" approach would appear to do even more to knock down walls separating technical fields. I prefer Justice Laddie's approach to CGK, as quoted in the ipkat article: "It includes all that material in the field he is working in which he knows exists..."

  2. I have a feeling that two things have been mixed up in this decision.
    If the "secondary article" was published before the filing date of the contested patent, this article is normal prior art and can be used in combination with another publication for an inventive step attack. If it can be demonstrated that the article could easily have been found on the internet by the skilled person, this supports the requirement that the skilled person was aware of the teaching of this piece of prior art, and that he could apply this knowledge to the teaching of an other prior art document anf therewith arrive at the claimed invention.
    However, CGK is something else than the contents of just a single prior art document. A document (e.g. handbook) in my opinion is not in itself CGK. Instead, it is evidence of CGK. So, the party relying on CGK in their argument has to demonstrate that what is written in the article is CGK, in other words, that its contents is generally known and accepted without question by the majority of people in this field. Whether or not this article can easily be found is in my opinion not particularly relevant for this. Furthermore, if it's real CGK, you can expect to find this knowledge in different publications, not just in this particular, single article.

  3. ... and then there were all the other things about the judgment. There seemed to me to be lots of jumping across chasams of reason to results.


  4. The Laddie reasoning appears most apt for CGK. It is, however, relevant that journal articles can be easily accessed via the internet, which would be a consideration when determining inventive step. The weight to which the skilled person would put on such a document being important. If great weight were placed on it, said document may find itself forming a paragraph or two of a textbook. Don't forget that textbooks are regularly updated. Once in said textbook, it may soon become "CGK according to Laddie".

    As to the main patent claim: In order to be entitled to such a monopoly, it is reasonable that the skilled person would be expected to conduct a search for relevant information. Patents should not be granted for inventions that a computer could create by combining known information. Such software already exists for linking scientific results.

    One must also not forget that the literature cited was in the same technical field, so no leap-of-technology Eureka moment was required.

  5. I would vehemently disagree with the premise that the US PHOSITA has a less prominent position vis a via what is labeled CGK.

    The not-so-recent case of KSR greatly expanded that CGK and with the changes in the AIA, the US level is by far the most extensive in any patent system in the world.

    As the foundation is shaky, I dare not enter the and climb the rest of the tower of this story.

  6. "if it's real CGK, you can expect to find this knowledge in different publications, not just in this particular, single article."

    Exacly righ. CGK for which the only evidence is a single scientific research paper, is not CGK.

  7. We can look at this as a re framing of the law:

    The decision seems to be suggesting that CGK includes those things which a person skilled in the art would come across when they set out to investigate the problem at hand.

    This narrows the person skilled in the art from a person in the field, to a far more specific category of 'a person in the field who had done preliminary research on the specific problem that the patent addresses', and would seem to increase their knowledge base considerably, as it would be expected to include things reasonably found but not otherwise known, and which might have been known to only a handful of people, if anyone, in the actual field.

    On the other hand, it could be seen as a modernization:

    What is the philosophical difference between looking at a reference manual in 1970's and the result of a keyword search of pubmed or another database in 2014? In both cases the results are 1) broader than the actual knowledge held by any one individual in the field 2) easily and likely to have been accessed by anyone in the field as a first step in addressing the problem.

    That a modern search can more easily jump between 'fields' is a result of the way fields have become both more specialized as more information is generated, and more open as superior indexing is available.

    As an aside I note that in Canada the CGK has also been described as including the results of a literature search: ex 2014 FC 638 at para 56 "...the common general knowledge of the skilled person or science the skilled person would have encountered through reasonably diligent research relating to the research questions before him (e.g. a literature search)."

  8. How to put this delicately....

    James, PHOSITA is an imaginery person, a legal construct - not someone who who actually be in a position to "check the records."

    As such, your stated view of "narrowing" just does not make any sense.

    Worse, the existing PHOSITA is already charged with the non-human power of omnipotence of all captured and written matter - something no human anywhere and under any circumstances can actually replicate.

  9. "An invention shall be taken to involve an inventive step if it is not obvious to a person skilled in the art, having regard to [the state of the art]".

    That is more or less all that the statute says, and that should always be borne in mind.

    James' argument seems to amount to "the case has redefined what the skilled person is" which, Mr. Anonymous, is entirely consistent with the skilled person being a legal construct (indeed, it is rather inconsistent with the skilled person being a real person because the existence or characteristics of a real person cannot be redefined by a legal decision).

    But I don't really agree that the skilled person has been redefined. The skilled person always did some research, the change, if there is one, seems to be in the type of research which would have been obvious to perform. That must be highly case-specific, and have a lot to do with how obvious it is to try to solve the problem never mind how obvious the solution is once you try.

    I don't think it can ever be right to say that an article in journal A is CGK but an article in journal B is not, because journal A is prestigious and widely-circulated and B isn't. I think it is correct to take into account the obviousness of performing a search on online databases, and if a search is obvious to perform and leads to an obvious solution to the problem then there is a lack of inventive step. But what searches are obvious to perform will be highly dependent on the problem being solved. In all situations there must be some searches which are obvious and some which are not.

    Remember, the statute says nothing about CGK. Perhaps the whole concept is becoming unhelpful and clouding the only real question: was it obvious?

  10. Let's ask the question: "was it obvious?"

    Ans. yes it was; oh no it wasn't; oh yes it was; oh no it wasn't!!! etc

    Needs something more Freddie. Which, is why judges, immediately after stating said obvious question (sorry, but you aren't the first to make the point), always follow with some rules on how to answer it.

  11. Freddie,

    I have to disagree with you.

    The legal construct has never "done research" as that is a real-life human activity which is not included in the legal construct.

    The legal construct is defined as already having knowledge (that any such "research" may - or may not unveil).

    Therefore, the thought of "doing research" does not fit into PHOSITA, because PHOSITA is not required to research what is out there - he KNOWS everything and anything that may be out there.

    James' argument is moot.

  12. Anonymous 1321, I completely agree and of course I am not the first to make the point. It is right that the case law provides some rules / guidelines about how to answer the obviousness question, for the sake of consistency and certainty apart from anything else.

    What I am saying is that in a discussion about the legal constructs created by those rules (such as this one: "what is the common general knowledge?"), it has to be remembered that the construct is a tool to discuss obviousness, and not lose sight of the original question. When there is discussion and controversy along the lines of "A is CGK because it was in this journal but B is not CGK because it was at the back of another journal, but what about C which was somewhere obscure but would have been found with a routine search?", I am worried that sight of the original question has been lost - that is all.

    Anonymous 1455, I'm not sure which I prefer out of "The legal construct has done research" and your preferred "The legal construct is defined as having knowledge", but I don't think it matters to my point about the original question being "is it obvious?". I think your disagreement with James probably boils down to semantics but I will leave that for him to pick up, if he wants to.

  13. Freddie,

    I have read your reply several times now and cannot make sense of it in regards to my posts and my disagreement with James.

    Perhaps this is a language/legal regime issue, as I operate under US law.

    There is a different aspect under US law that determines which art the PHOSITA has knowledge of (bearing in mind, still, that the concept of "research" is still very much inappropriate).

    That different aspect is covered in the portion of the phrase ITA: In The Art, and stems from the differences in what art is applied per 102 (ALL art) and what art is applied per 103 (not ALL art).

    For 103 purposes, the "world" of prior art is limited based on the legal construct - see the US case of Graham v John Deere for how this different sphere of prior art is determined, as modified by the US case of KSR which broadens that sphere of prior art to include arguably nonanalagous art fields as long as the solution contained in those nonanalagous art fields bears on the solution that the inventor has come up with.

    However, even this understanding does NOT admit to a level of "routine search" as postulated by James.

    Therefore, my comments stand.

  14. There is a serious drawback in the logic presented:

    It is common knowledge that (at least in the States), many large corporations forbid their workers from reading - or even looking at - published patents and patent applications (for fear of treble damages).

    Arguably, under the logic in the article, this would mean that patents and patent applications themselves could not serve accepted prior art as such are NOT "form[ing] part of the common stock."

    A most bizarre result.

  15. The concept you are describing is not new. It is called “secondary common general knowledge,” a term coined by Mr Arnold, now Arnold J, and adopted by Warren J in Actavis UK Ltd v Novartis AG [2009] EWHC 41 (Ch) at [71], [124] - [136] aff’d [2010] EWCA Civ 82 (referring to, but not specifically approving of “secondary common general knowledge” at [52(h)]. The same concept, though not by that name, is used in Nutrinova Nutrition Specialities & Food Ingredients GmbH v Scanchem UK Ltd [2001] FSR 42 at [81] (Pumfrey J) and Ivax Pharmaceuticals UK Ltd v Akzo Nobel NV [2006] EWHC 1089 (Pat), [2007] RPC 3 (Lewison J) at [55]-[61]. In See Actavis and Ivax the secondary CGK was determination of the properties of the pharmaceutical in question, while in Neutrinova it was knowledge of existing methods of synthesizing pharmaceutical in question. I should add that by saying it is not new, I do not mean to say it is necessarily right. Indeed, the concept was specifically rejected by the High Court of Australia in Aktiebolaget Hässle v Alphapharm Pty Ltd [2002] HCA 59 at [55].


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