Mr Justice Arnold gave a decision on 25 November in the matter Merck Sharp and Dohme Limited v Shionogi & Co Limited. The case concerned EP (UK) 1 422 218 B1 which relates to the use of integrase inhibitors of a particular formula for the preparation of the pharmaceutical composition for use as an integrase inhibitor for preventing or treating a viral disease.
The formula disclosed and claimed 1039 compounds. Mr Justice Arnold held that the evidence showed that, at best, it was plausible that a tiny fraction possess integrase inhibitory activity in a biochemical assay. Further, Mr Justice Arnold held that it does not begin to make it plausible that substantially all the compounds covered by [the formula] possess anti-viral activity or would be effective in preventing or treating a viral disease. He therefore held the patent to be invalid on the ground that the claimed invention lacked an inventive step.
Counsel for the patentee argued that the claim was limited only to those compounds which were effective, but Mr Justice Arnold held that such a functional limitation could not be relied upon: This is because the technical problem which was required plausibly to be solved if the claimed invention was to make a technical contribution to the art was the provision of compounds which had such activity. The identification of a very large class of compounds only some of which had such activity would not make a technical contribution to art, and it made no difference that the claim was limited to the compounds which did have activity.
Mr Justice Arnold also found that the patent presents the skilled team with a vast research project with a high likelihood of failure. The evidence showed that it would take 9.6x1030 years to assay just 0.01% of the claimed compounds and that there was therefore an undue burden on the skilled person to perform the invention across the scope of the claim. He therefore held the patent to be invalid on the ground of insufficiency of disclosure.
The judge pointed out that the patentee had not identified a product within the claim to take forward for clinical trials and, with reference to the alleged infringement, raltegravir:
284.The upshot is that, on any view, the Patent presents the skilled team with a vast research project with a high likelihood of failure, but claims the results if they happen to succeed even if (as in the case of raltegravir) such success has nothing to do with the teaching of the Patent. Accordingly, it is not possible to perform the claimed inventions across the scope of the claim.
The full decision is available here.