To summarise: Teva had applied for revocation of Merck’s European Patent (EP(UK) 0509752), relating to “ophthalmic compositions comprising combinations of [MK 507] and [timolol]” for the treatment of glaucoma. At first instance, the case had come before Floyd J who held ( EWHC 2952 (Pat), noted by tytoc collie here) that the patent was invalid; the relevant claims either being obvious or containing added matter. Merck appealed.
The core issue before the Court related to the Patent’s inventive step, or rather the lack of it – the parties having agreed that if the Judge’s conclusion on obviousness was upheld then the issue on added matter would not arise.
The prior art in question, referred to throughout the judgment as “Nardin”, had been published only six days before the priority date of the patent. Teva alleged that this publication rendered the invention obvious. Merck, as might be expected, took the opposite view. However, rather than arguing that the gap between Nardin and the patent was too large to be deemed an obvious step to take, Merck took a radically different approach. It accepted that discovering what adjustments needed to be made to the directions in Nardin would have been a matter of trial and error not involving any inventive step, but suggested that conducting the trials and correcting the errors would take a substantial period of time. Given Nardin was only six days older than the patent, it was contended that the skilled team would have been unable to make the changes in the time available to them. Therefore, even if the addressee had discovered the signposts in Nardin, they would have been wandering round in the dark for more than the six days that in fact existed between its publication and the patent’s priority date. Merck also argued that the Judge had wrongly applied hindsight in concluding that the skilled team starting with Nardin would end up with something falling within the relevant claim. “If, as the judge had decided, the development of such a co-formulation would not qualify for patent protection why spend the time and money necessary for its development”?
The Chancellor, with whom Richards and Patten LJJ agreed, was having none of it. He noted, after referring to the relevant statutory provisions, that:
 “There is no additional time requirement… If by reference to the relevant state of the art the invention is obvious then it matters not that it may take time to perform the necessary routine tests. It is a matter of simple comparison between the relevant art and the claimed invention.”Merck’s second proposition, that the judge had used hindsight, received equally short shrift:
 “Counsel for Merck submitted that the reasoning of the judge involved no fewer than 23 steps, 17 from the first stage and 6 from the second. He claimed that such a quantity was unparalleled and itself indicative of the use of hindsight. I would reject this submission. The first ten in the first stage are different elements in the relevant state of the art and the eleventh is the conclusion the judge drew from them. It seems to me that the first stage involves one step only, namely embarking on the project which Nardin suggested.”The argument that obvious steps will not be taken because no patent protection would arise at the end was also roundly rejected:
 “The true test is whether the improvement involves an inventive step, not a commercially attractive one.”And so, another one bites the dust...