This article was first published in The World Intellectual Property Report March 2009.
The High Court held that Novartis’ patent for a sustained release formulation of the drug fluvastatin sodium was invalid as being obvious over the common general knowledge.
The patent claimed an invention related to sustained release compositions comprising a water-soluble salt of fluvastatin as the active ingredient. Fluvastatin sodium (“Fluvastatin”) is a member of the group of drugs known as the statins which are used to reduce patients’ cholesterol levels. At the priority date of the patent, four statins had been approved for use in humans, Lovastatin, Simvastatin, Pravastatin and Fluvastatin. At the priority date, Fluvastatin as well as the other three statins were on the market in their immediate release form.
Actavis attacked the patent on the basis of obviousness, insufficiency and added matter. Novartis sought amendment of the patent and counterclaimed for infringement.
Claim 1 was to a sustained release pharmaceutical composition comprising a water-soluble salt of fluvastatin as active ingredient in particular types of sustained release formulations wherein the active ingredient was released over more than three hours. There was nothing in the claim as to the performance of the sustained release composition in vivo and the examples in the Patent were all tested in vitro. Accordingly, Warren J. construed the term “sustained release” in the Patent to mean a formulation which releases its active ingredient in vitro over a period of more than three hours.
Common general knowledge
Warren J. considered the topic of common general knowledge in some detail. It was important to differentiate between matter which was in the public domain at the priority date of the patent and matter which can be properly regarded as common general knowledge. Common general knowledge means the information which at the date of the patent is known and accepted without question by the skilled person in the art. Evidence that a fact was known, or even well-known to a witness does not mean it is common general knowledge. A piece of information in a scientific paper does not become common general knowledge because it is widely read but nor is it necessary to show that the information is known in the sense that it has been memorised by the skilled person. Material which is known to exist and to which the skilled person would refer to as a matter of course, even 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 is part of the common general knowledge.
Differentiating between common general knowledge and what is known by some is often difficult. This is particularly so in light of the modern ability to circulate and retrieve information. Employees of large companies may have access to extensive information resources and will be aware of information soon after publication; others, without such advantages, may not be aware of such information until it is accepted generally and put into practice. The notional skilled person is the ordinary man who may not have the advantages of access to extensive information resources.
“Secondary” common general knowledge is the information in addition to actual common general knowledge which the skilled person would obtain as a matter of routine before tackling the problem at hand (Nutrinova v Scanchem  FSR 42 at ). The skilled person would discover this information on his literature search and would read such documents with the eyes of the skilled person and therefore as an unimaginative person skilled in the relevant art.
It does not follow, however, that all papers that could be found by the skilled person(s) conducting a diligent search form part of the general knowledge. Warren J. observed that, if information resulting from the search and that “would be generally accepted once discovered” was treated as forming part of the common general knowledge this would cause difficulties. What the expert giving evidence himself takes away from a paper may not be what the unimaginative skilled person would take away. However, substituting the words “would regard as highly probably to be reliable” for “would be generally accepted once discovered” was, in Warren J’s view an acceptable approach to this concept. In Nutrinova, Pumfrey J. had taken the view that publications of this sort must be pleaded, if only to avoid surprise. Warren J. doubted whether Pumfrey J. was seeking to lay down an inflexible rule but rather had been highlighting a desirable practice.
On the issue of obviousness, there was a dispute between the parties about the effect on the case of the decision of the House of Lords in Conor v Angiotech ( UKHL 49,  RPC 28) and so Warren J. considered the House of Lords judgment in detail.
Warren J. first set out some general propositions on the law of obviousness, noting that obviousness is a question of fact and that a qualitative, not quantitative, test is applied by the Court. Warren J. noted that the primary evidence is that of the properly qualified expert whose function is to assist the court in determining whether the relevant step would have been obvious to a skilled person having regard to the state of the art. Evidence as to what persons in the art did or did not do, is secondary evidence, which could be relevant but needed to be firmly kept in its place.
In assessing obviousness, the Court must consider the matter from the perspective of the relevant skilled person, which includes the positive and negative aspects of his common general knowledge as well as his attitudes and perceptions, his preferences and prejudices. Warren J. accepted that one of the factors the court will take into account in its assessment is a consideration of what problem or need the skilled person is trying to solve or meet. It did not follow however, that because the need is already met or the problem already solved, that improvements or different solutions cannot be obvious. It was also relevant to consider whether there was any motive to take the step in question from the prior art when deciding whether it was an obvious one. The skilled person is also deemed to look at and read publicly available documents however obscure they may be. He never misses the obvious, nor stumbles on the inventive. It does not matter whether there are a number of obvious routes. Providing the route in question is obvious, the claim is invalid.
Warren J. noted that in addressing the question of obviousness, it is always important to guard against hindsight and that it is frequently appropriate but not compulsory to apply the structured approach to obviousness set out in Windsurfing ( RPC 59) as reformulated in Pozzoli ( EWCA Civ 588).
On Conor, Warren J. stated that Lord Hoffman had identified the principle at stake as being about how one identifies the concept embodied in the invention which constitutes the inventive step. To identify the concept, it was critical to ask the right question. If Pumfrey J., the Judge at first instance, had asked himself the right question, he would have found the patent to be non-obvious. In so far as Conor is an authority for a principle of wider application, it is that the question of obviousness is to be determined by reference to the claim and not to some vague paraphrase based upon the extent of the disclosure in the description. In terms of something being ‘obvious to try’ this was useful in a case in which there was a ‘fair expectation of success’. How much of an expectation of success would be needed depended on the particular facts of the case, including the factors identified by Kitchin J. in Generics v Lundbeck ( RPC 32 at 72):
“The question of obviousness must be considered on the facts of each case. The court must consider the weight to be attached to any particular factor in the light of all the relevant circumstances. These may include such matters as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues of research, the effort involved in pursuing them and the expectation of success.”
In considering the effect of Conor on Pozzoli, where the allegation of obviousness was being denied on the basis that there was a prejudice against the alleged invention, Warren J. noted that in Jacob LJ’s judgment, there was a strong flavour of the reasoning which could be found in his judgment in Conor. This reasoning, with its reference to the contribution to human knowledge by the inventor did not find favour with the House of Lords.
Warren J. commented, however, that restricting the enquiry strictly to the claim would result in a surprising result. If the invention works and if the patent tells the reader enough to work the invention, it should not, on this strict approach, be necessary to give any explanation at all about why or how the prejudice has been overcome. That, however, would be an unacceptable result. The patent would be granted where the claim is to an invention which is an old idea that is thought not to work without the applicant giving any explanation at all why the prejudice is wrong. Lord Hoffman had recognised that there is a threshold test of plausibility. Where the invention involves overcoming a prejudice against an old idea, the specification much disclose enough at least to make the invention plausible. There must be some reason to justify the conclusion that something which was thought not to work would, after all, work perfectly well. If no reason was given then the patent cannot be justified but this would be because the description does not support the claim, not because the claim is obvious.
Further, Warren J. noted that in Pozzoli, Jacob LJ. was considering a single prejudice which prevents the invention from being obvious. He did not address the position where there is some other factor which might be sufficient to meet an obviousness attack. In Warren J’s opinion, a patentee does not need to address such a factor in the patent before he can rely on it as a defence to an obviousness attack. The question of obviousness is one of fact which cannot depend on what the patentee has included in his patent.
Applying Kitchin J. in Generics v Lundbeck, Warren J. considered the prospect of success of the project as the most important single factor in this case. Having comprehensively considered all of the evidence and parties arguments, Warren J. held that the motivation for, and prospects of success of, the project with which the skilled team is notionally engaged was uncertain. Subject to a consideration of whether the invention was technically obvious, this alone would render the claims non-obvious.
Warren J. then went on to consider whether the invention would be technically obvious quite apart from the notional project. This reasoning was based on the 5 ¼ inch plate argument derived from Laddie J’s judgment in Hoechst Celanese Corp v BP Chemicals Ltd  FSR 547 at 573, that is, whether a step from the prior art, albeit made without reason, can still be obvious. Whether there is a reason for taking the step is an important consideration, although not an essential requirement for a conclusion of obviousness (Pharmacia Corp v Merck & Co Inc.  EWCA Civ 1610). The only argument against obviousness was that nobody would have thought of actually producing such a formulation; there would have been no motivation to do so. On the facts of the case, this absence of motivation did not prevent the claims from being technically obvious over the common general knowledge.
Warren J’s discussion of the effect of Conor on Pozzoli is interesting as is his final approach to the question of whether the claims were obvious. Also of interest, is the Judge's analysis of "secondary" common general knowledge, which may have implications for litigators deciding whether such information should be specifically pleaded.