Apimed Medical Honey Ltd v Brightwake Ltd (t/a Advancis Medical)

This is a dispute about honey and its use in medical dressings. The appellant (“Apimed”) is the proprietor of European Patent (UK) No 1,237,561 (“the Patent”) for an invention entitled “Medical dressings comprising gelled honey”. In this action it claimed that the defendant (“Brightwake”) had infringed the Patent by making and selling a medical dressing called Algivon. Brightwake denied infringement and counterclaimed for revocation of the Patent on the grounds that it lacked novelty or was obvious.

The action came on for trial before HHJ Fysh QC in the Patents County Court. In his judgment handed down on 14 January 2011 he held that the Patent was not infringed and was invalid for obviousness. He rejected the allegation of lack of novelty.

Apimed, represented by Mr Richard Miller QC and Mr Geoffrey Pritchard, now appeals against the finding of invalidity. It originally also appealed against the finding of non-infringement. However, Apimed and Brightwake have reached a settlement in respect of this appeal and consequently Brightwake no longer has any interest in its outcome. Accordingly, the finding of non-infringement is not pursued. Apimed nevertheless wishes to establish that the Patent is valid and, in accordance with the guidance given by this court in Halliburton Energy Services Inc v Smith International (North Sea) Ltd [2006] EWCA Civ 185; [2006] RPC 26, the Comptroller was invited to consider whether he wished to appear or make written submissions on the appeal on the basis that his costs would be borne by Apimed. The Comptroller indicated that he did indeed wish to appear and has been represented on this appeal by Mr Mitcheson. He has properly recognised that the Comptroller’s role is to protect the public interest by intervening to the extent necessary to prevent invalid patents being restored to the Register. He has assisted the court considerably by rehearsing the counter-arguments to Apimed’s appeal, while at the same time maintaining a balanced view consistent with his position.

This issue on this appeal is therefore whether the judge was right to hold the Patent invalid for obviousness. Mr Miller contends that the judge fell into error for a raft of reasons to which I shall shortly turn. Mr Mitcheson says that the judge was right, essentially for the reasons he gave.

I should also mention that, despite his finding that the allegation of lack of novelty failed, the judge said at [128] that the Patent was invalid both for lack of novelty and obviousness. This was plainly a mistake and I need say no more about it.

The curative properties of honey have been known since ancient times. Professor White, who gave expert evidence on behalf of Brightwake, explained that the use of honey for treating wounds is described in the Ebers Papyrus which was written in about 1500 BC and the Patent itself says its use for this purpose is recorded in 4000 year old Sumerian clay tablets.

Honey did not, however, find a place in modern wound care, at least in the UK. Conventional treatments have involved the use of gauze dressings and, more recently, hydrocolloid dressings which provide a moist wound environment which is thought to be beneficial for wound healing.

Nevertheless, the early 1990s saw a resurgence of interest in the biological properties of honey and its use in wound healing prompted by a growing body of evidence that it has a complex combination of activities which give it anti-microbial and anti-inflammatory properties. One of the most prominent researchers in the field has been Professor Molan, the inventor of the Patent.

The Patent has a priority date of 9 December 1999 and the specification begins with a description of the technical field. It explains that the invention is directed to the use of honey in medical dressings and that the honey is modified with a gelling agent, resulting in compositions in the form of a flexible sheet or a pliable putty which can be used as a wound covering.

The specification then describes the background to the invention, the use of honey in treating wounds for thousands of years and the recent attention it has attracted with the discovery that its effectiveness is due primarily to its anti-microbial properties.

It continues that recent investigations have involved attempts to maintain raw honey in contact with a wound as part of a moist dressing. However, the methods used in these investigations, though useful for trial purposes, are said to be relatively time consuming and impractical for a number of reasons. First honey is runny at body temperature and so is difficult to retain at the wound site. Second, many wounds exude moisture which dilutes the honey, reducing its effectiveness and making it even harder to contain.

The problem addressed by the Patent is thus identified in paragraph [0017] as being the provision of a composition which allows the potential use of honey as a practical dressing for wounds and other medical uses to be realised.

Against this background, the specification then proceeds to disclose the invention. In substance it is the provision of a medical composition for dressing wounds comprising the combination of honey with one or more natural based gelling agents, in which the amount of gelling agent is such that the resulting composition takes the form of a flexible sheet or pliable putty that can be readily moulded to fit the wound to which it is to be applied, and in which at least 50% (by weight) of the composition is honey.

Paragraph [0048] explains that such a putty may be moulded or plied into shape by finger pressure so allowing the thickness of the resulting composition to be varied, and allowing it to be moulded for use in particular applications and locations.

Paragraphs [0050] and [0051] continue that the invention may also take the form of a sheet which can be laid over a wound. This may be pre-formed into a particular shape or size or cut or trimmed as required. Typically such a sheet will be flexible enabling it to accommodate different contours and major irregularities on the surface to which it is applied.

Paragraph [0057] explains that the invention may, in its simplest form, be implemented by combining honey with a suitable viscosity increasing agent. The specification continues that there are a number of suitable such agents available, including gums and polysaccharides, alginates, and both synthetic and natural polymeric compounds, all of which are well known in the art.

The specification then contains a series of examples. Example 1, described in paragraphs [0070] to [0076], is of some importance to this appeal. It involves the use of sodium alginate as the gelling and viscosity increasing agent. It explains that finely powdered sodium alginate is blended with honey warmed to approximately 60˚C, but not to any significantly higher temperature so as to avoid degradation of any hydrogen peroxide producing enzymes in the honey. It continues that as the alginate slowly dissolves and absorbs water from the honey, a gel begins to form and that the mixture should therefore be stirred so that any unblended and ungelled alginate does not settle out. The blend of honey and alginate may then be either rolled into a sheet or formed into a putty. In addition, fillers and additives such as fibres may be introduced while the gelling process is occurring.

The specification concludes with a series of claims. For the purposes of this appeal, I need only to refer to claim 1 which calls for:

(i)

a medical composition for dressing wounds comprising

(ii)

the combination of one or more honeys with one or more natural based gelling agents,

(iii)

wherein the amount of gelling agent in the composition is such that the resulting composition is in the form of a flexible sheet or

(iv)

a pliable putty that can be readily moulded to fit the wound to which it is to be applied,

(v)

and wherein at least 50% (by weight) of the composition is honey.

A patent specification is addressed to those likely to have a practical interest in the subject matter of the invention and practical knowledge and experience of the kind of work in which the invention is intended to be used: Catnic Components Ltd v Hill Smith Ltd [1982] RPC 183 at 242 to 243. The claims of the patent must be understood as if read by him and he is the person who must be considered for the purpose of assessing obviousness and sufficiency. More recently, in Schlumberger Holdings Ltd v Electromagnetic Geoservices AS [2010] EWCA Civ 819, [2010] RPC 33 Jacob LJ, with whom Sullivan and Waller LJJ agreed, explained that, in the case of some inventions, notably those where the patent itself can be said to be ‘art changing’, the person skilled in the art may not be the same for the purposes of obviousness on the one hand, and claim interpretation and insufficiency on the other.

This consideration led Jacob LJ to identify as a key issue the particular problem the patentee was trying to solve. This in turn leads to a consideration of the art in which the problem lay and, so also, the notional team in that art, as Jacob LJ explained at [65]:

“65.

In the case of obviousness in view of the state of the art, a key question is generally “what problem was the patentee trying to solve?” That leads one in turn to consider the art in which the problem in fact lay. It is the notional team in that art which is the relevant team making up the person skilled in the art. If it would be obvious to that team to bring in different expertise, then the invention will nonetheless be obvious. Likewise if the possessor of the “extra expertise” would himself know of the other team’s problem. But if it would not be obvious to either of the notional persons or teams alone and not obvious to either sort of team to bring in the other, then the invention cannot fairly be said to be obvious. As it was put in argument before us the possessors of the different skills need to be in the same room and the team with the problem must have some reason for telling the team who could solve it what the problem is.”

This is not a case in which it can be said that the invention was art changing. Nor did the judge treat it as such. At [38], he said the team would have surgical and commercial experience in the field of wound treatment. He elaborated upon this at [40] in these terms:

“In more concrete terms, the team would, I consider, be deemed to be already working within the adequately resourced R&D department of a manufacturer of contemporary surgical dressings which (if required) could rely upon a consultative combination with persons concerned with the in situ treatment of wounds with commercially available dressings - such as tissue viability nurses (TVNs) and specialist consultants. I do not therefore consider that the team should include alginate chemists, rheologists, epidemiologists, materials scientists, honey experts and so on. This is a technically simple patent and in this case pitching the notional addressee at the right technical level is important.”

Apimed does not quarrel with this formulation. It contends the judge fell into error, however, in finding at [37] that the team must be deemed to have some interest in the possible use of honey for modern wound care. Mr Mitcheson submitted, and I agree, that this criticism is misconceived for two reasons.

First, it is wrong as a matter of law. The skilled person is deemed to read the prior art with at least some level of interest. It was put this way by Aldous LJ in Asahi Medical Co Ltd v Macopharma (UK) Ltd [2002] EWCA Civ 466:

“21.

I will come later to analyse the judge’s reasoning, but first make it clear that a decision on obviousness does not require a conclusion as to whether or not the skilled person would be slightly, moderately or particularly interested in any document. The court has to adopt the mantle of the skilled person. That mantle will include the prejudices, preferences and attitudes that such persons had at the priority date. Thereafter the court has to decide whether the step or steps from the prior art to the invention were obvious. That decision has to be taken without the invention in mind and through the eyes of the skilled person. Of course any prior art document relied on must be deemed to be read properly and in that sense with interest. To conclude otherwise would deprive the public of their right to make anything which is an obvious modification of a published document. By obvious I mean that which would be obvious to the skilled person. The correct approach was set out by Oliver LJ in the Windsurfing case. He said at page 74 line 20:

‘We agree, of course, that one must not assume that the skilled man, casting his experienced eye over Darby [the prior art], would at once be fired with knowledge that here was something which had a great commercial future which he must bend every effort to develop and improve, but he must at least be assumed to appreciate and understand the free-save concept taught by Darby and to consider, in the light of his knowledge and experience, whether it would work and how it will work.’”

Second, it is wrong as a matter of fact. The skilled person would have been interested in honey as a result of his common general knowledge, an issue to which I now turn.

The common general knowledge of the notional skilled addressee is all that knowledge which is generally known and generally regarded as a good basis for further action by the bulk of those engaged in a particular art: Beloit Technologies Inc v Valmet Paper Machinery Inc [1997] RPC 489 at 494 to 495. It may also go a little further, as Laddie J said in Raychem Corporation’s Patent [1998] RPC 31 at 40, approved on appeal at [1999] RPC 497 at 503 to 504:

“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 memorised 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. In this case, for example, the general technical discussion of conductive polymers in the Cabot technical report was common general knowledge well before the priority date. So too would be the general teaching in the leading articles and textbooks on the subject.”

The judge referred to these and other cases at [46] but is criticised by Apimed for failing thereafter to set out the principles that he intended to apply.

I do not believe that this criticism has any substance in the context of the present case. The judge referred to Beloit and a series of other cases from which the relevant principles are, I believe, entirely clear. Moreover, if the judge had misunderstood those principles it would have become apparent in the way he approached the particular factual issues before him, namely whether or not honey and alginate dressings formed part of the common general knowledge.

As for honey, the judge dealt with this [47]-[49]. He referred to a series of publications before him including, most importantly, The Journal of Wound Care which was described as “the Bible” for the skilled addressee. The April and September 1999 issues included a series of articles on the modern therapeutic use of honey in wound treatment. The April issue carried on its front cover the headline “Honey Research - an investigation of antibacterial activity” and included an editorial entitled “Honey and wound bacteria”. It also carried an article by Dr Cooper and Professor Molan entitled “The use of honey as an antiseptic in managing Pseudomonas infection”. This article referenced a series of further articles detailing the antibacterial properties of honey and concluded that, when applied directly to a wound, honey with an average level of antibacterial activity might be expected to be effective in preventing the growth of pseudomonads on the wound surface and possibly deeper into the wound. However, it continued, further clinical trials were needed to find which type of honey gave the best therapeutic results, and what minimum level of antibacterial activity was necessary in the honey for it to be effective as a topical antiseptic treatment for infected wounds.

The September issue contained a comprehensive review paper by Professor Molan entitled “The role of honey in the management of wounds” which referenced over 60 clinical papers. This review paper (“the Molan paper”) formed Brightwake’s principal attack on the Patent on the ground of obviousness.

The judge also heard expert evidence upon this issue. For example, Professor White explained that since the early 1990s a clearer understanding of the biological properties of honey had caused a surge of interest which spread to the UK from Australia and New Zealand and this was reflected in an increase in the number of published articles relating to the use of honey in the treatment of wounds. He was also in no doubt that by 1999 the skilled addressee considered the use of honey in wound care as a “hot topic” and it was often discussed by practitioners at conferences. Overall I believe the judge had ample material upon which to make these findings:

“49.

In fact, though Molan’s cited article may not as such be an item of common general knowledge, by the priority date much of its contents in my view, was. For example, having in particular regard to the evidence of Professor White, the following I consider, formed part of the common general knowledge in the UK (in no particular order):

(a)

That honey had antibacterial/antimicrobial properties and that such properties had been the subject of clinical trial.

(b)

That a number of varieties of honey were commercially available and, being a natural product, its antibacterial activity may be expected not to be uniform, some honeys being more efficacious than others.

(c)

That a medical practitioner would normally prefer to use as pure a therapeutic product as he could obtain. This would equally (and automatically) apply to honey. Though its provenance was ‘natural’ and thus free of possible processing contaminants, honey might contain undesirable hive contaminants.

(d)

That if was thought prudent or necessary, decontamination could be effected by γ-irradiation (which was itself a well-known process for doing this in general pharmaceutical practice).

(e)

That one could apply liquid honey direct into an open wound and, if necessary, cover it in situ to stop it running out.

(f)

That the general rheological properties of natural honey were widely known - and not just to the skilled addressee. It is usually runny, it is non-uniform in taste appearance etc, it will crystallise over time, it can be returned to a liquid condition by putting the honey jar on a radiator, it absorbs water and also dissolves in it – and so on.”

It also follows that the judge was entitled to find that the skilled addressee would have had “an interest” in the possible use of honey for wound dressings, as he did at [37].

The second aspect of the common general knowledge concerned alginate dressings. The judge found that these were a matter of common general knowledge. Two in particular were readily available. The first, called Sorbsan, was made of calcium alginate and the second, called Kaltostat, was made of sodium-calcium alginate. Both were made in the form of felts, that is to say layers of randomly deposited fibres. By December 1999 these dressings were not only widely available in hospitals and clinics but had largely replaced the use of cotton gauze in the treatment of highly exuding wounds.

The judge also considered that the skilled person would have been aware of the general use of alginates in a variety of industries for their thickening and film-forming properties. In particular, they were used in the pharmaceutical and food industries for the thickening of liquids to create jellies and the like.

Two important points emerge from these findings. First, there was never any suggestion that sodium alginate, as opposed to calcium or sodium-calcium alginate, was commonly used in connection with the production of dressings. Second, the available alginate dressings took the form of felts and so had a structure characteristic of such materials.

The judge had to decide a number of issues as to the proper interpretation of claim 1 of the Patent. His findings are not challenged on this appeal, but one of them has a particular bearing upon it, namely the meaning of the expression “natural based gelling agents”. Brightwake contended that the claim requires an agent which causes the honey to form a true gel, that is to say a soft solid which has dimensional stability such that it deforms if a load is applied to it but returns to its original shape and dimensions when the load is removed. Apimed contended that the expression is not so limited and includes agents which cause an increase in the viscosity of the honey sufficient to allow it to be made into a putty or a rolled sheet.

The judge preferred the interpretation contended for by Apimed. A significant part of his reasoning focused on the description in the Patent of the use of particulate sodium alginate. When added to honey this does not give rise to a true gel but increases the viscosity of the honey and creates something which the judge called “long chain entanglement”. This, the experts agreed, though not a gel, is akin to a gel. Yet, upon Brightwake’s interpretation, and despite forming the basis of all but one of the examples of the Patent, it would not fall within the scope of the claims. Hardly surprisingly, the judge considered that such a result would be odd, if not perverse.

Calcium alginate behaves rather differently. It is insoluble in honey and does not act as a gelling agent or even as a viscosity increasing agent. Its activity may be illustrated by the behaviour of Brightwake’s own product Algivon which consists of honey applied to a calcium alginate felt pad. Dr Kershaw, Brightwake’s expert on this issue, explained that the calcium alginate is a fibrous felt material which would not generally be described as a viscosity increasing agent in the food or medical arenas. The individual polymer chains are held together within the calcium alginate, do not go into solution in the applied honey, and do not thereafter form a new polymer network. Moreover, calcium alginate is a thermally irreversible structure in that it will chemically decompose before it melts. It is therefore very stable in aqueous solution.

It followed that, upon the judge’s interpretation, a calcium alginate dressing could not be described as a “natural based gelling agent” and the application of honey to such a dressing did not produce a product falling within claim 1 of the Patent. It necessarily followed that the claim for infringement failed.

Brightwake advanced an argument that the Patent lacked novelty over the prior use by Mrs Sylvie Hampton of alginate and gauze dressings at her hospital in Eastbourne. Specifically, she used Sorbsan and Kaltostat dressings “packed” with Gale’s honey that she bought in her local supermarket. Plainly these dressings did not fall within the scope of claim 1 of the Patent upon the construction for which Brightwake primarily argued. It nevertheless relied upon the prior use as a traditional “squeeze” argument on the basis that if the claim was sufficiently broad to catch Algivon then it must be invalid over Mrs Hampton’s prior use.

The judge rejected the allegation of lack of novelty, as he was bound to do in the light of his finding as to the proper interpretation of claim 1. However, he recognised the problem the prior use posed for Apimed at [102]:

“For present purposes, the physical attributes of these [Mrs Hampton’s] wound dressings must have been identical to those possessed by ALGIVON - because they were made in the same way. In both, the calcium alginate acts simply as a mechanical carrier for the honey. This is indeed a squeeze for Apimed.”

The judge found the Patent obvious over the Molan paper. As I have explained, this was published in September 1999 shortly before the priority date. It begins with the observation that the widespread development of antibiotic-resistant bacteria has generated an increasing interest in the use of alternate therapies for the treatment of infected wounds and says that the paper examines how the chemical and physical properties of honey may facilitate wound healing and offers guidance on practical issues related to clinical use.

The paper continues with a description of the various actions of honey, namely an antibacterial action which is thought to be due primarily to the presence of hydrogen peroxide, a deodorising action, a debriding action and an anti-inflammatory action. It also explains that honey stimulates tissue growth.

The paper then describes the clinical experience of the use of honey to treat a number of different wound types and offers the following “guidelines for practice”:

“Guidelines for practice

Honey varies in consistency, from liquid to solid, with the glucose content crystallised. Solid honeys may be liquefied by warming and semi-solid honeys can often be liquefied by stirring. Heating above 37˚C should be avoided, as this may burn the patient and will destroy the enzyme that produces hydrogen peroxide.

The honey should be spread evenly on the dressing pad rather than directly to the wound. The amount of honey required on a wound depends on the amount of exudation; the beneficial effects of honey on wound tissues will be reduced or lost if small quantities of honey become diluted by large amounts of exudate. Wounds with deep infection require greater amounts of honey to obtain an effective level of antibacterial activity by diffusion into the wound tissues.

Dressing technique

Typically, 30mL of honey is used on a 10cm x 10cm dressing. Dressing pads impregnated with honey (such as those produced by REG International, New Zealand) (Figs 1 and 2) are the most convenient way of applying honey to surface wounds. Occlusive or absorbent secondary dressings are needed to prevent honey oozing out from the wound dressings. (Fig 3). The frequency of dressing changes will also depend on how rapidly the honey is diluted by exudates. Daily dressing changes are usual, but up to three times daily may be necessary. Exudation should be reduced by the anti-inflammatory action of honey, so the frequency of dressing changes should decline as treatment progresses. Deep wounds (Figs 4-6) or abscesses are most easily filled by using honey packed in ‘squeeze-out’ tubes, now available commercially (Actimel) (Fig 7).”

A number of points emerge from this passage. First, it teaches that solid honeys may be liquefied by warming and semi-solid honeys may often be liquefied by stirring. Thus, contrary to the teaching of the Patent, this paper contemplates softening honeys and reducing their viscosity. Second, it describes the spreading of honey on a dressing pad. Typically, it says, 30ml of honey is used on a 10cm x 10cm dressing and this results in impregnation of the pad. Pads produced by a company called REG International are said to be suitable and there was no dispute at trial that these were in fact gauze. Third, an alternative method of application is described which involves squeezing honey from a tube directly in to a deep wound. Importantly, there is no description here of what may be said to be the heart of the invention of the Patent, namely the use of a gelling agent to increase the viscosity of the honey to such a degree that it can be formed into a flexible sheet or a pliable putty without the need for any separate dressing at all.

The paper concludes:

“This paper has described the chemical and physical properties of honey and has shown how these may have a positive influence on wound healing. Honey is an ideal substance to use as a wound dressing material. Its fluidity, especially when warmed, allows it to be spread and makes honey dressings easy to apply and remove. The osmotic action resulting from honey’s high sugar content draws out wound fluid and thus dilutes the honey that is in contact with the wound bed, minimising adhesion or damage to the granulating surface of the wound when the dressing is removed. The high solubility of honey in water allows residual honey to be washed away by bathing.

Although the clinical experiences detailed in this paper show positive results, more quality randomised controlled trials are needed to provide evidence to encourage the use of honey in wound care.”

Once again, this conclusion emphasises that honey is an ideal substance to use as a wound dressing material and that its fluidity, especially when warmed, allows it to be spread and makes honey dressings easy to apply and remove.

The judge began his consideration of obviousness over the Molan paper by reminding himself that it is convenient to address the issue using the structured approach explained by this court in Pozzoli SpA v BDMO SA [2007] EWCA Civ 588, [2007] FSR 37:

The judge also directed himself, entirely properly, that in the case of relatively simple inventions it is particularly important to be wary of hindsight; that it may be appropriate to take into account any “mindset” amongst those skilled in the art; and that, at the end of the day, the crucial question is whether or not the invention is technically rather than commercially obvious.

The judge had earlier considered the person skilled in the art, the common general knowledge and the claimed invention and he therefore turned to consider the third Pozzoli step, namely what, if any, differences existed between the matter described in the Molan paper and claim 1 as he had construed it, and the fourth step, namely whether those differences constituted steps which would have been obvious to the person skilled in the art or whether they required any degree of invention. He dealt with these issues relatively shortly:

“112.

The nature of the dressings which Professor Molan used is not however revealed – though their source is. There is thus a missing element in the Windsurfing progression set out in para 103 above, item (3). The evidence is clear regarding alginate dressings at the time (as sodium or calcium alginate or a mixture thereof.); their availability was commercial and their use was common general knowledge. These dressings were not only widely available commercially in the UK (see above) but in cases of exudate being present, were actually the dressings of choice. There is evidence of this from Mr Gray T2/191-192, and 270 and from Professor White in White I, I/1/55-56 and T4/469. Mrs Hampton also gave evidence to the same effect about the use of alginate dressings, adding that she preferred the closer ‘weave’ of the alginates in order better to retain the honey.

113.

I have no doubt that the skilled person reading Professor Molan’s article would at once and without hesitation, have in mind commercial sodium and calcium alginate dressings as being the dressings of choice to use in following his directions – assuming he did not go to REG Internat’l itself. In my judgment, all the independently defended claims of the Patent are therefore obvious in the light of the Molan article.

114.

For the avoidance of doubt, the ‘fancy’ honeys which are now the subject of the proposed amendment to the Patent claims 11(a) to (c), cannot in my view afford patentable subject matter over and above the unamended claims; it was common general knowledge that different honeys offered different levels of efficacy - but they are all honeys.”

The judge therefore identified the only difference between the state of the art and the inventive concept of the claim as being “alginate dressings”. He proceeded to consider whether or not it was obvious to use these dressings in place of the gauze dressings described in the Molan paper and concluded that it was. On that basis, he found that all the claims were obvious in the light of that disclosure.

In my judgment it is clear that the judge fell into error at this point. The only dressings which he had found formed a part of the state of the art were the calcium alginate and sodium-calcium alginate dressings sold under the brand name Sorbsan and Kaltostat respectively. But, on the judge’s own findings as to the proper interpretation of claim 1 of the Patent, the application of honey to these dressings would not produce a gel within the scope of the claimed monopoly. Indeed, this was precisely the reason why the judge had himself rejected the allegation of anticipation over Mrs Hampton’s prior use. The real difference between the disclosure of the Molan paper and the inventive concept of claim 1 of the Patent lay not in the adoption of a calcium or sodium-calcium dressing in place of a gauze dressing but rather in having the idea of discarding such a dressing altogether and, instead, using a gelling agent such as particulate sodium alginate to increase the viscosity of the honey to such a degree that it could be rolled into a sheet or formed into a putty without the need for any dressing at all. There is no teaching in the Molan paper whatsoever that this was an obvious step to take. Indeed, the teaching in the paper is to the contrary: that the honey may be liquefied by warming before application to a dressing pad or, alternatively, squeezed from a tube directly into a deep wound.

I recognise that an appellate court will not ordinarily reverse a trial judge’s finding on obviousness unless he has made some error of principle: see, for example, Biogen Inc v Medeva plc [1997] RPC 1 at 45; Lundbeck A/S v Generics (UK) Ltd [2008] EWCA Civ 311, RPC 19 at 23. Nevertheless, for the reasons I have given, I believe that the judge did here fall into an error of principle in two respects. First, he failed to identify the correct differences between the Molan paper and claim 1; second, he failed to address the critical question whether, viewed without any knowledge of the alleged invention, the differences constituted steps which would have been obvious to the person skilled in the art or whether they required any degree of invention.

The judge also found the Patent invalid for obviousness over the common general knowledge. He dealt with this very shortly at [118]:

“The case under this head is put clearly and succinctly by Professor White: White I, I/1/130-131.The problem of retention and application of honey, he says, may obviously be solved by making the honey thicker by using any medical thickening agent –and (see above) many were available. That is, I consider, realistically the end of all the claims which are independently defended.”

In light of his earlier finding of obviousness over the Molan paper I can quite understand the judge addressing the allegation of obviousness over the common general knowledge as shortly as he did. But that finding having been shown to be unsound, I believe that the reasoning of the judge in this paragraph is wholly inadequate to maintain a finding of invalidity of the Patent. It is well established that an obviousness argument based upon common general knowledge alone must be treated with caution because it is unencumbered with any detail which might point to non-obviousness and is particularly likely to be tainted with the impermissible use of hindsight. In Abbott Laboratories Ltd v Evysio Medical Devices UCL [2008] EWHC 800 (Pat), [2008] RPC 23 I said this:

“180.

It is also particularly important to be wary of hindsight when considering an obviousness attack based upon the common general knowledge. The reason is straightforward. In attacking a patent, attention is focussed upon the particular development which is said to constitute the inventive step. With this development in mind it may be possible to mount an attack which is unencumbered by any detail which might point to non obviousness: Coflexip SA v Stolt Comex Seaway Ltd (CA) [2000] IP&T 1332 at [45]. It is all too easy after the event to identify aspects of the common general knowledge which can be combined together in such a way as to lead to the claimed invention. But once again this has the potential to lead the court astray. The question is whether it would have been obvious to the skilled but uninventive person to take those features, extract them from the context in which they appear and combine them together to produce the invention.”

With this warning in mind, it can be seen that the judge has failed to identify the aspect of the common general knowledge which is said to constitute the starting point for the obviousness analysis. Second, he has failed to identify the precise difference between that starting point and the inventive concept of the Patent. In this regard it is not enough simply to make the honey thicker. The invention requires increasing the viscosity of the honey to such a degree that it may be rolled into a sheet or used as a putty without applying it to a traditional dressing. Third, as to whether it was obvious to take the step from the common general knowledge to a product in claim 1, Professor White, in the paragraph of his report which the judge referred to at [118], simply stated that an obvious way to address the problem of application and retention was to make the honey thicker, to use for this purpose a thickening agent and that alginate was an obvious candidate because it was commonly used in the wound environment. But the only way it was used in the wound environment was in the form of the calcium alginate or sodium-calcium alginate pads which, for the reasons I have given, do not act as a gelling agent as called for by claim 1. Moreover, Apimed’s expert upon this issue, Mr David Gray, responded to Professor White’s evidence in his second report and explained why he disagreed with it. Specifically, he explained that runniness of the honey was not a significant issue and could be dealt with by a gauze or similar dressing. He was not cross examined upon that evidence and the judge made no reference to it.

The Comptroller served a respondent’s notice before the hearing of this appeal seeking to raise as an additional ground for upholding the finding of the judge that Mrs Hampton’s prior use of honey with Kaltostat deprived at least claim 1 of the Patent of novelty and rendered all of the claims obvious. Mr Mitcheson sought to contend that Kaltostat contained a mixture of calcium alginate and sodium alginate in a proportion of 80:20% and that the sodium alginate portion would act as a gelling agent.

This matter was not raised before the judge, was not developed in evidence and was not addressed by the judge in his judgment. It raises technical issues which are quite impossible to resolve upon this appeal. For these reasons we declined to allow the Comptroller to take this new point and so indicated during the course of the hearing.

For the reasons I have given, I would allow this appeal.

I agree

I also agree