Pharmacia Corp, GD Searle & Co and Pfizer Inc (the patentees) were the proprietors of European Patent (UK) 0 679 157 (the patent) relating to chemical compounds having use as non-steroidal anti-inflammatory drugs (NSAIDs). The patentees appealed the findings at trial that the patent was invalid and not infringed by the defendants, Merck & Co Inc and Merck Sharp & Dohme Ltd (Merck). On appeal, the finding of invalidity was confirmed (Court of Appeal, December 14 2001). Merck's chemical compound, sold under the name Vioxx, was held to fall within claim 1 and would have infringed if the claim had not been held invalid.