Factual and Procedural Background
This case concerns a patent dispute involving Company A, proprietor of European Patent (UK) No 1,237,561 ("the Patent") for an invention titled "Medical dressings comprising gelled honey". Company A alleged that Company B infringed the Patent by manufacturing and selling a medical dressing called Algivon. Company B denied infringement and counterclaimed for revocation of the Patent on grounds of lack of novelty or obviousness.
The trial was held before Judge Fysh QC in the Patents County Court, who ruled that the Patent was not infringed but was invalid due to obviousness, rejecting the lack of novelty claim. Company A appealed against the invalidity finding. The infringement appeal was settled and not pursued further. The Comptroller intervened in the appeal to protect the public interest in preventing invalid patents from being restored.
The central issue on appeal was whether the trial judge was correct to hold the Patent invalid for obviousness.
Legal Issues Presented
- Whether the Patent was invalid for obviousness.
- Whether the Patent lacked novelty (an issue rejected by the trial judge and not pursued on appeal).
- The proper construction of claim 1 of the Patent, particularly the meaning of "natural based gelling agents".
- Whether prior use and common general knowledge rendered the Patent invalid.
Arguments of the Parties
Appellant's Arguments
- The trial judge erred in finding the Patent invalid for obviousness for multiple reasons.
- The judge incorrectly identified the differences between the prior art (notably the Molan paper) and the inventive concept of the Patent.
- The judge failed to properly consider whether the differences required any degree of invention.
- Company A contended that the skilled addressee should not be deemed to have an interest in honey for wound care, a point rejected by the court.
Respondent's Arguments (Comptroller and Company B)
- The trial judge was correct in holding the Patent invalid for obviousness.
- The Patent was obvious in light of the Molan paper and common general knowledge.
- The skilled addressee would have had an interest in honey for wound care and the relevant common general knowledge included the biological properties of honey and the use of alginate dressings.
- The Comptroller sought to raise an additional ground regarding prior use involving a specific alginate composition but was not permitted to do so on appeal due to lack of evidence.
Table of Precedents Cited
| Precedent |
Rule or Principle Cited For |
Application by the Court |
| Halliburton Energy Services Inc v Smith International (North Sea) Ltd [2006] EWCA Civ 185; [2006] RPC 26 |
Guidance on the role of the Comptroller in patent appeals and public interest intervention. |
Used to justify Comptroller's participation to protect the public interest in preventing invalid patents from being restored. |
| Catnic Components Ltd v Hill Smith Ltd [1982] RPC 183 |
Definition of the skilled addressee for patent interpretation and obviousness assessment. |
Applied to identify the skilled person with practical knowledge in the relevant art. |
| Schlumberger Holdings Ltd v Electromagnetic Geoservices AS [2010] EWCA Civ 819; [2010] RPC 33 |
Distinction between skilled persons for obviousness and claim interpretation in art-changing inventions. |
Confirmed that this was not an art-changing invention, so the same skilled person was applied for both purposes. |
| Asahi Medical Co Ltd v Macopharma (UK) Ltd [2002] EWCA Civ 466 |
The skilled person reads prior art with interest but without inventive hindsight. |
Applied to reject the appellant's argument that the skilled person lacked interest in honey for wound care. |
| Beloit Technologies Inc v Valmet Paper Machinery Inc [1997] RPC 489 |
Definition and scope of common general knowledge. |
Used to define the common general knowledge relevant to the skilled addressee. |
| Raychem Corporation's Patent [1998] RPC 31; approved [1999] RPC 497 |
Explanation of the technical background forming common general knowledge. |
Supported the understanding of common general knowledge including textbooks and trade literature. |
| Pozzoli SpA v BDMO SA [2007] EWCA Civ 588; [2007] FSR 37 |
Structured approach to assessing obviousness in patent law. |
Followed stepwise to analyze obviousness of the Patent over prior art. |
| Biogen Inc v Medeva plc [1997] RPC 1 |
Appellate court's approach to findings of obviousness and errors of principle. |
Referenced regarding the standard for appellate review of obviousness findings. |
| Lundbeck A/S v Generics (UK) Ltd [2008] EWCA Civ 311; RPC 19 |
Standards for appellate review of obviousness decisions. |
Applied as authority for appellate intervention in obviousness findings. |
| Abbott Laboratories Ltd v Evysio Medical Devices UCL [2008] EWHC 800 (Pat); [2008] RPC 23 |
Warning against hindsight in obviousness attacks based on common general knowledge. |
Used to caution against simplistic obviousness conclusions without detailed analysis. |
| Coflexip SA v Stolt Comex Seaway Ltd (CA) [2000] IP&T 1332 |
Risks of hindsight in combining common general knowledge to attack patent validity. |
Supported the need for careful analysis to avoid hindsight bias in obviousness assessment. |
Court's Reasoning and Analysis
The court began by confirming the identity and attributes of the skilled addressee, who would be a team with surgical and commercial experience in wound treatment, but not including specialized experts such as alginate chemists or honey experts. The skilled person was deemed to read prior art with some interest, including knowledge of honey's properties and alginate dressings.
The court reviewed the common general knowledge, finding that by the priority date the antibacterial and therapeutic properties of honey were well known and that alginate dressings (calcium and sodium-calcium alginate felts) were widely used in wound care.
On claim construction, the court accepted the trial judge's interpretation that "natural based gelling agents" included agents that increased viscosity sufficiently to form a putty or sheet, not necessarily requiring a true gel. This interpretation excluded calcium alginate felts as gelling agents within the claim scope.
The court examined the prior art, including the Molan paper, which described honey's properties and clinical use but did not teach the use of a gelling agent to form a flexible sheet or putty of honey without a separate dressing. Instead, the Molan paper contemplated honey being warmed and spread or squeezed onto dressings.
The trial judge found the Patent obvious over the Molan paper by substituting alginate dressings for gauze dressings. The appellate court identified this as an error of principle because the alginate dressings found in the prior art were not within the claim scope and did not produce the claimed gelled honey composition. The true inventive step was the use of particulate sodium alginate to gel honey into a putty or sheet without a traditional dressing, a step not taught or suggested by the prior art.
Regarding obviousness based on common general knowledge, the court found the trial judge's reasoning inadequate. Making honey thicker was not enough; the invention required a viscosity increase sufficient for forming a mouldable sheet or putty. Evidence from experts showed that the only alginate use in wound care was in felt pads, which did not act as gelling agents, and the skilled person would rely on dressings to manage runniness rather than modify honey's viscosity as claimed.
The Comptroller's attempt to introduce a new ground regarding sodium alginate content in a prior product was rejected due to lack of evidence and procedural fairness.
Holding and Implications
The court ALLOWED the appeal, overturning the trial judge's finding of patent invalidity for obviousness.
The direct effect is that the Patent is to be regarded as valid, at least on the issue of obviousness as addressed on this appeal. No new precedent was established beyond the application of established principles of patent law regarding obviousness, claim construction, and common general knowledge.