Pharmacia Corporation & Ors v Merck & Co Inc & Anor, Court of Appeal - Civil Division, December 14, 2001, [2001] EWCA Civ 1610,[2002] RPC 41,[2002] ENPR 10
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Pharmacia Corporation & Ors v Merck & Co Inc & Anor, Court of Appeal - Civil Division, December 14, 2001, [2001] EWCA Civ 1610,[2002] RPC 41,[2002] ENPR 10
Case No: A3/2000/0422
Neutral Citation Number: [2001] EWCA Civ 1610IN THE SUPREME COURT OF JUDICATURECOURT OF APPEAL (CIVIL DIVISION)ON APPEAL FROM CHANCERY DIVISIONMR JUSTICE PUMFREYRoyal Courts of JusticeStrand, London, WC2A 2LLFriday 14th December 2001B e f o r e :LORD JUSTICE ALDOUSLORD JUSTICE SEDLEYand LADY JUSTICE ARDEN- - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - -(Transcript of the Handed Down Judgment ofSmith Bernal Reporting Limited, 190 Fleet StreetLondon EC4A 2AGTel No: 020 7421 4040, Fax No: 020 7831 8838Official Shorthand Writers to the Court)- - - - - - - - - - - - - - - - - - - - -Mr David Kitchin QC and Mr Richard Meade (instructed by Bristows for the Appellants)Mr David Young QC, Mr Justin Turner and Mr Thomas Hinchliffe (instructed by Lovells for the Respondents)- - - - - - - - - - - - - - - - - - - - -JudgmentLORD JUSTICE ALDOUS:1. The appellants G.D. Searle & Co, the Pharmacia Corporation and Pfizer Inc. are the proprietors of European Patent (UK) 0 679 157. I will refer to them as the patentees. They alleged that that patent had been infringed by Merck & Co Inc. and Merck Sharp & Dohme Limited by amongst other acts the manufacture and sale of a non-steriodal anti-inflammatory (NSAID) sold under the trademark Vioxx, but referred to by Merck as MK-966. 2. Merck accepted that they had carried out the allegedly infringing acts, but denied infringement and submitted that the patent was invalid upon a number of grounds. Pumfrey J upheld those submissions. His decision is challenged by the patentees in this appeal. 3. The appeal involves issues which require knowledge of a difficult area of chemistry. I am indebted to the judge for his full and clear exposition of the chemistry, the issues involved and his reasons for coming to the conclusions that he did. It has lightened the considerable burden involved in this appeal. The Patent4. The background - The patent was published on 2nd November 1995 and claims priority from a U.S application filed on 15th January 1993. It is entitled ``Novel 3,4-Diaryl Thiophenes and Analogs Thereof Having Use as Antiinflammatory Agents''. Such compounds would be recognised by the addressee of the specification as NSAIDs. They are well known drugs which include aspirin, paracetamol and ibuprofen. As is commonly known they can cause gastro-intestinal ulceration. Research in 1971 suggested these drugs had the ability to inhibit synthesis of a prostaglandin produced by the body during inflammation. This is because known NSAIDs directly inhibited what is called COX. The addressee of the specification would have been appraised of the common general knowledge of those working in that field. The judge summarised that knowledge in these passages of his judgment. ``5. I take the following account of the development of the understanding of the action of NSAID's from Professor Flower's evidence, which was unchallenged on this issue. There are two major classes of anti-inflammatory compounds, the steroids and the NSAID's. In 1971, Sir John Vane and his colleagues discovered that aspirin, indomethacin and sodium salicylate had the ability to inhibit the synthesis of prostaglandins, and suggested that this was the major mode of operation of these drugs. Prostaglandins are chemicals which play a part in inflammation. There are a number of prostaglandins, and they are responsible for many of the body's regulatory functions. The ones in which Vane was interested were those which were produced by the body during inflammation. They are synthesised in the body from arachidonic acid and other fatty acids via an enzyme then called prostaglandin H synthase, then fatty acid cyclooxygenase, and finally COX. Vane showed that NSAID's directly inhibited COX in cell-free tissue extracts in vitro. This discovery explained the tendency of the NSAID's, to cause stomach irritation and ulceration. The drugs cause the irritation because they inhibit the synthesis of the prostaglandin which is responsible for regulating the secretion of acid in the stomach and the secretion of the mucus which protects the lining of the stomach against being digested.6. This elucidation of the action of NSAID's led immediately to a method of screening potential drugs for aspirin-like activity without having to perform in vivo experiments. Provided that a source of COX was available, the enzyme could be exposed to the drug, and its ability to synthesise prostaglandin from arachidonic acid could be measured. If the drug successfully inhibited COX, little arachidonic acid would be used to synthesise prostaglandin and the amount produced could be measured. At this time, all the enzyme available had to be derived from animal tissue; so there was dog spleen COX, rabbit brain COX, and so on....10. Once the discovery of COX had been made, those responsible for the development of NSAID's, having available an assay for the a...See the full content of this document
