Asahi Medical Co Ltd v Macopharma (UK) Ltd; Macopharma S.A.

For obviousness, the court must identify the inventive concept, consider the skilled person’s common general knowledge and attitudes at the priority date, identify the differences from the prior art, and decide whether those differences were obvious without hindsight. The skilled person is taken properly to read and understand the prior art, but need not be assumed to have exceptional commercial enthusiasm for it.

A reason or commercial incentive for making a modification may be relevant, but it is not an essential condition of obviousness. A technically obvious variation remains unpatentable even if no one would have wished to implement it. A claim ending with centrifugation did not, on its construction, require the resulting layers to be separately expressed into useful products.

The claimant appealed from Laddie J in the Chancery Division, who had held European Patent (UK) 0349188 invalid for obviousness. The patent concerned a closed blood-processing system in which whole blood was filtered to remove leukocytes before centrifugation.

The claimant contended that claim 1 required the production of at least two useful separated blood products, that the judge had misconstrued claim 4, and that the judge had approached obviousness incorrectly. It argued in particular that the skilled person would have had no sufficient motivation to implement or modify the prior art.

The central issues were the construction of the claims and whether converting the disclosed whole-blood filtration arrangements into a fully closed system involved an inventive step.

1. Appeal dismissed unanimously. Lord Justice Aldous held, with whom Lord Justice Tuckey and Lord Justice Jonathan Parker agreed, that the relevant claims were invalid for obviousness.

2. Claim 1 ended with centrifugation. It did not require the layers then produced to be transferred into satellite bags, or require the production of multiple useful blood products. The specification distinguished centrifugation from subsequent separation. Claim 4, read with claim 2, likewise concerned separation into layers by centrifugation. The inventive concept was therefore filtration of whole blood in a closed system before conventional blood processing.

3. The court applied the structured analysis in Windsurfing [1985] RPC 59. The court must assess obviousness through the eyes of the ordinarily skilled but unimaginative person, with that person’s contemporary prejudices, preferences and knowledge. The prior-art document is deemed to have been properly read and understood. The ultimate statutory question remains whether the differences between it and the invention were obvious.

4. Motivation can be relevant where the inventive step lies in perceiving that a step can be taken or will have a particular effect. It is not, however, an indispensable precondition. The absence of a commercial reason to make an obvious workshop variation does not make that variation inventive. The public are entitled to make obvious modifications of what has been disclosed.

5. Frey-Wettstein disclosed filtering whole blood and centrifuging it, but used an open or almost closed arrangement. By the priority date, the advantages of a closed system for avoiding contamination and permitting storage were known. Making the disclosed arrangement fully closed by pre-assembling its standard components under sterile conditions was an obvious workshop variation. Further conventional separation after centrifugation added nothing inventive.

6. Asahi 286 also disclosed a filter suitable for filtering whole blood while preserving platelets. Using it in a closed system with subsequent centrifugation was technically obvious. The judge was entitled to prefer the evidence supporting that conclusion.

• Court of Appeal (Civil Division) — dismissed the claimant’s appeal: [2002] EWCA Civ 466.
• Chancery Division (Laddie J) — held the patent invalid for obviousness on 5 December 2000; no citation was stated in the judgment.