Sweet success for patent holder: gelled Manuka honey medical dressing non-obvious

Authors: Clive Thorne and Henry Priestley (RPC)

Apimed Medical Honey Ltd v Brightwake Ltd [2012], Court of Appeal, EWCA Civ 5, 20 January 2012

Journal of Intellectual Property Law & Practice (2012), doi: 10.1093/jiplp/jps124, first published online: August 30, 2012

This decision of the Court of Appeal, England and Wales, provides a useful overview of the correct principles to be applied when assessing common general knowledge and obviousness. In such cases, where a successful appellant has the validity of its patent restored, it should seek a certificate of contested validity from the court.

Legal context

In this patent infringement case the defendant ran a defence of non-infringement and counterclaimed for revocation of the patent on the grounds that it was not novel and was obvious. At first instance the case was heard in the Patents County Court (PCC) by Judge Fysh, who found the patent invalid for obviousness, lack of novelty and no infringement. Apimed appealed to the Court of Appeal.

Facts

Clinical evidence from recent studies shows that certain types of honey, particularly Manuka honey, are effective at treating serious wounds where bacteria have developed a resistance to conventional treatments. However, given the physical properties of honey at room temperature, there is an inherent problem as to its use as a practical wound dressing.

Apimed solved this problem by changing honey's physical state into a solid compound. By combining alginate powder and honey, a pliable putty or flexible sheet can be created and easily applied to a wound site. Apimed's patent for this invention is European Patent (UK) No 1,237,561 for ‘medical dressings comprising gelled honey’.

Apimed licensed their invention to Brightwake, which was able to exploit the patent in manufacturing wound dressings. Upon expiration of the licence, Apimed issued an infringement claim against Brightwake. Brightwake denied infringement and counterclaimed for revocation.

The parties settled their dispute before the appeal hearing, so the only issue to be determined by the Court of Appeal was whether the patent was valid. The settlement meant that Brightwake did not oppose Apimed's appeal on this point and played no part in the appeal hearing. This position is undesirable from a public policy perspective as an uncontested appeal as to validity increases the risk that an invalid patent is restored to the register of patents (because an appellant's submissions as to why its patent is valid go unchallenged). However, the Comptroller General of Patents was requested before the Court of Appeal and made active submissions on behalf of the public interest. This enabled a certificate of contested validity to be granted.

Analysis

The decision at first instance misapplied the test for assessing whether a patent is obvious over prior art. The leading appeal judgment, given by Kitchin LJ, clarified the main principles to be applied by the court when it is asked to consider whether a patent is invalid for obviousness.

The skilled addressee
Kitchin LJ held that a patent specification is addressed to those likely to have a practical interest in the subject matter of the invention of the patent 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 242–243).

It is the skilled addressee who is the person to be considered for the purpose of assessing obviousness and sufficiency, but Kitchin also noted that where the patent is ‘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 (as per Jacob LJ in Schlumberger Holdings Ltd v Electromagnetic Geoservices AS [2010] EWCA Civ 819).

It was also held that, as a matter of law, the skilled addressee is deemed to read the prior art with at least some level of interest (Aldous LJ in Asahi Medical Co Ltd v Macopharma (UK) Ltd [2002] EWCA Civ 466). Therefore, in this case, persons skilled in the art must be deemed to have some interest in the possible use of honey in modern wound care.

Common general knowledge
Kitchin LJ ruled that the common general knowledge of the 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. This could include ‘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’ (Laddie J in Raychem Corporation's Patent [1998] RPC 31 at 40, approved on appeal at [1999] RPC 497 at 503–504).

Obviousness over the prior art
Kitchin LJ held that, although the trial judge was correct to follow the steps in Pozzoli SpA v BDMO SA ([2007] EWCA Civ 588) when assessing whether a patent is obvious over prior art, he erred in their application. The Pozzoli steps are as follows:

* Identify the notional person skilled in the art and the relevant common general knowledge of that person;

* Identify the inventive concept of the claim in question or, if that cannot readily be done, construe it;

* Identify what, if any, differences exist between the matter cited as forming part of the ‘state of the art’ and the inventive concept of the claim or the claim as construed;

* Ask whether those differences, viewed without any knowledge of the alleged invention as claimed, constitute steps which would have been obvious to the person skilled in the art or whether they require any degree of invention.

Kitchin LJ held that the trial judge did not correctly identify the differences between the state of the art and the inventive concept of the claim and consequently failed to identify correctly whether the differences constituted steps which would have been obvious to the person skilled in the art or whether they required any degree of invention. On that basis the appeal was allowed, the patent held valid and a certificate of contested validity was ordered by the Court of Appeal (the consequences of which are explained below).

Practical significance

Although this decision does not raise new principles of law, it provides a useful summary of the correct approach the court must take when assessing whether a patent is obvious. It also provides an example of the court, upon a successfully contested appeal of invalidity and the application of the appellant, ordering a certificate of contested validity. This can be of commercial value to a patent owner, for example when negotiating future licences, as the validity of its patent has been proved. This can be seen by the world at large since the certificate is entered on the patents register at the Intellectual Property Office. It could also deter future infringers, since a defence of invalidity in a subsequent action would be pointless if run on similar grounds to the unsuccessful challenge.

Further, if a defendant in a subsequent action proceeded with a validity challenge and lost, it could be liable to pay the claimant's costs on an indemnity basis. This applies even if the case is heard in the PCC for which a £50,000 costs recovery cap usually applies. In Polymer v D S Smith, Judge Birss confirmed that, where a certificate of contested validity is granted after invalidity proceedings either before a court or the Comptroller, the PCC costs cap is not applied in subsequent invalidity proceedings against the patent in the PCC.