Cephalon Inc & Ors v Orchid Europe Ltd & Ors

Patent claims must be construed purposively in their technical and factual context. Where the specification, common general knowledge and industry practice show that particle size is measured on the input active pharmaceutical ingredient, literal wording referring to particles in the composition does not require measurement after manufacture.

For obviousness, a regulatory dissolution threshold does not define the optimum formulation. The skilled team may be expected routinely to investigate particle-size reduction where it offers a confident expectation of improved dissolution and bioavailability, unless a significant technical obstacle is established. A product claim may be sufficiently enabled by one method of making the product, but process or use claims may fail for insufficiency where the skilled person cannot identify whether the claimed process or use has been carried out.

Cephalon, the proprietor and licensees of three patents concerning modafinil formulations, sued Orchid and Mylan for infringement. Mylan denied infringement and challenged validity for obviousness and insufficiency. The principal construction issue was whether the claimed particle-size measurements referred to particles in the finished dosage form or to the input active pharmaceutical ingredient used in manufacture.

The court also considered obviousness over Drugs of the Future and common general knowledge, and, alternatively, an application by Nguyen. The central questions were the proper construction of the claims, whether the claims were infringed on that construction, and whether they were valid.

1. Construction. The claims were construed purposively, applying the approach stated in Kirin Amgen v TKT [2005] RPC 9 and discussed in Virgin v Premium Aircraft [2009] EWCA Civ 1062. The skilled formulator would understand the references to particle size as referring to measurements of the input bulk active pharmaceutical ingredient. The patent described its experiments in those terms, particle size was not ordinarily measured in a solid dosage form, and no common general knowledge method existed for doing so. Literal readings of the claims were rejected as impractical.
2. Infringement. On the proper construction, the Orchid input material fell outside the claimed particle-size ranges. There was therefore no infringement. The court nevertheless found, on the alternative construction, that particles extracted from the tablets were representative of particles in the tablets, while stressing that this factual finding did not affect construction.
3. Obviousness. Applying the structured approach in Pozzoli v BDMO [2007] EWCA Civ 588, the claimed inventive concept was the use of reduced particle-size modafinil in a formulation. The skilled team would have had a strong expectation that reducing particle size would improve dissolution and bioavailability, would routinely test the claimed ranges, and would encounter no significant technical obstacle. A regulatory target defined acceptability, not the optimum formulation. The claims were obvious over Drugs of the Future and common general knowledge.
4. Further validity issues. The Nguyen attack was unnecessary but would have succeeded against claims limited only by the 95 per cent particle-size criterion. Insufficiency did not arise on the correct construction. If the alternative construction had been adopted, the 962 use claims and 549 process claim would have been insufficient, although the 698 product claims would not.
5. Disposition. All three Cephalon patents were invalid for obviousness. Had they been valid, they would not have been infringed.