Generics (UK) Ltd v Daiichi Pharmaceutical Co Ltd & Anor

Obviousness under patent law is governed by the statutory question, not by any rigid judicial formula. The Windsurfing/Pozzoli questions, the problem-and-solution approach and “obvious to try” are tools for answering that question. A route is obvious to try only where it would occur to the skilled person and carry at least a fair expectation of success.

Common general knowledge includes information which the skilled person would consult as a matter of course. Mere ready availability is insufficient.

For supplementary protection certificates, a racemate comprising two biologically active enantiomers is a combination of active ingredients. Its marketing authorisation is not necessarily the first authorisation for a separately patented, novel and inventive enantiomer having distinct activity, bioavailability and toxicity.

The claimant appealed from Kitchin J’s decision, [2008] EWHC 2413 (Pat), upholding a patent for levofloxacin and the supplementary protection certificate based upon it. The patent challenge on appeal was confined to whether levofloxacin was obvious in light of a poster describing the resolution of a different quinolone, flumequine.

The claimant also contended that earlier marketing authorisations for ofloxacin, the racemic mixture containing levofloxacin, were the first authorisations for levofloxacin under Regulation 1768/92. The central issues were whether the skilled person would have followed the poster’s method with a fair expectation of success and whether the racemate and the separately patented enantiomer were the same “product” for certificate purposes.

1. The appeal was dismissed. Kitchin J had made no error of principle in holding the patent valid. Ward and Lloyd LJJ agreed with Jacob LJ.

2. The governing inquiry under article 56 of the European Patent Convention and section 3 of the Patents Act 1977 is whether the invention was obvious to the skilled person in light of the state of the art. The Windsurfing/Pozzoli questions provide a helpful structure, but neither they nor “obvious to try” or the problem-and-solution approach may replace the statutory question. A route is obvious to try only if it would occur to the skilled person and offer at least a fair expectation of success.

3. The poster did not make the claimed enantiomer obvious. Flumequine was no longer influential, the resolving agent was unusual, and the poster resolved an intermediate rather than the final racemate. The method of making ofloxacin was not common general knowledge merely because it could readily be found. There was no reason why a skilled person reading the poster would search for and compare the two intermediates. Even if the comparison were made, the reaction might or might not work and many alternatives existed. The judge was entitled to find that the route lacked sufficient attraction and predictability.

4. Common general knowledge comprises the stock of information which guides the skilled person from the outset, including material which would be consulted as a matter of course. Information does not enter that stock merely because it is readily available. A specific prior-art document is read with common general knowledge, not automatically together with every other searchable document.

5. The supplementary protection certificate was valid. Under article 1(b) of Regulation 1768/92, ofloxacin was a combination of two significantly active ingredients. Its earlier authorisations therefore concerned the combination, while the later authorisation for levofloxacin was the first for that active ingredient alone. Levofloxacin was not a minor variant or an inactive-impurity case. It was a separately patented, novel and inventive product with distinct activity, solubility and toxicity.

6. Article 3 did not preclude the certificate. Read purposively with Regulation 1610/96, it permits protection for a separately patented novel and inventive enantiomer notwithstanding an earlier authorisation for the racemate. The interpretation was clear, so no reference to the European Court of Justice was required.

• Court of Appeal (Civil Division): By [2009] EWCA Civ 646, unanimously dismissed the claimant’s appeal and upheld both the patent and supplementary protection certificate.
• High Court, Patents Court: Kitchin J, in [2008] EWHC 2413 (Pat), held the patent and the supplementary protection certificate valid.