Molylycke Health Care v Brightwake

In a patent obviousness appeal, the challenger bears the burden of proving that the claimed invention was obvious. Obviousness is a multifactorial judgment, and appellate courts must exercise particular caution when reviewing a specialist patent judge. That restraint does not permit a finding based on a technical route unsupported, or contradicted, by the expert evidence. The skilled addressee’s mindset at the priority date forms part of the state of the art. A step which appears simple in retrospect is not necessarily obvious. The court must assess whether the prior art supplied a genuine motivation to take the proposed route, without hindsight.

Molnlycke was the proprietor of European Patent 0633757 for a wound dressing. It alleged that Brightwake’s Episil products infringed claim 6. The Chancery Division held that the products did not infringe and that the relevant claims were invalid for obviousness over Brassington, although the novelty attack failed.

After settlement, Brightwake did not participate in the appeal. The infringement issue had become academic, and the Court of Appeal therefore considered whether the finding of obviousness was sustainable. The central issue was whether Brassington made it obvious to use an apertured plastics carrier with silicone gel on the wound-facing side and a different, non-tacky silicone coating on the other side.

The Court of Appeal unanimously allowed the appeal on the obviousness issue. Since infringement had become academic, the court expressed no view on whether the trial judge’s infringement conclusion was correct.

1. The court accepted the structured obviousness inquiry stated in Pozzoli Spa v BDMO SA & Anr [2007] EWCA Civ 588: identify the skilled person and common general knowledge; identify or construe the inventive concept; identify the differences from the prior art; and ask, without knowledge of the alleged invention, whether those differences were obvious.
2. A granted patent is prima facie valid, so the burden of proving obviousness rests on the challenger. Obviousness is a multifactorial question of judgment. Following Biogen Inc v Medeva Plc [1997] RPC 1, an appellate court must be especially cautious when reviewing a specialist patent judge’s evaluation.
3. That caution does not prevent intervention for an error of principle. A finding of obviousness must be based on evidence. Properly qualified expert evidence is primary evidence, as explained in Mölnlycke AB and Another vs Procter & Gamble Limited Number 5 [1994] RPC 49. The warnings in Panduit Corporation v Band-It Co Ltd [2002] EWCA Civ 465 and Security Ltd v Siemens Schweiz AG [2008] EWCA Civ 1161 reinforced the danger of a judge pursuing an unsupported technical route of his or her own.
4. The trial judge treated Brassington as supplying a solid motivation to coat the non-wound side of a plastics film with non-tacky silicone. Read in context, the relevant passage did not provide that motivation. The only expert evidence on the point was that such a coating would be wasteful and pointless. The judge’s proposed route was therefore contrary to the evidence and failed to account for the skilled addressee’s mindset. That was an error of principle, and the finding of obviousness could not stand.

1. Court of Appeal (Civil Division): allowed Molnlycke’s appeal on the finding of obviousness, [2012] EWCA Civ 602. The infringement issue was academic and was not determined.
2. Chancery Division: His Honour Judge Birss QC held that the Episil products did not infringe claim 6 and that the contested claims were invalid for obviousness over Brassington. The novelty attack failed.