Some patent cases make this fairly non-technical Kat glaze over a bit when he tries to make head or tail of the facts. One such case is Generics [UK] Ltd (t/a Mylan) v Yeda Research And Development Co Ltd and Teva Pharmaceutical Industries Ltd  EWCA Civ 925, decided yesterday by a three-man Court of Appeal for England and Wales which consisted of two specialist IP judges -- Lords Justices Kitchin and Floyd --
together with Lord Justice Moses.
In the Patents Court, England and Wales, Mr Justice Arnold disappointed Mylan by holding the patent to be both valid and infringed [on which, see David Brophy's excellent Katpost here]. However, that judge kindly agreed to Mylan being allowed to appeal, which it duly did.
The Court of Appeal dismissed the appeal in no uncertain terms, in a judgment delivered by Lord Justice Floyd, with which his brethren concurred. In the Court's view:
* The alleged prior art in Johnson would have left the skilled team in a state of uncertainty as to what was being used in the phase III trial, and it was highly unusual for a material to be changed in any substantial way in the course of a series of trials. Arnold J was entitled to conclude, given the lack of clarity as to the molecular weight of the material in the Johnson trial, that the skilled team would not have considered it worthwhile to include the lower weight material in further testing.
* The rule that a technical effect relied on had to be made plausible by the specification, and could not be established for the first time by subsequent evidence, did not provide a basis for the different rule arrived at by the judge as to whether subsequent evidence could be used to negate an effect made plausible by the specification. However, Arnold J was entitled to reach the conclusion that it was made plausible by the specification that there was a connection between lower molecular weight and reduced toxicity and reaction. He was also entitled to conclude that Mylan had not proved that difference in molecular weight made no difference.
* Arnold J was correct to reject the appeal based on insufficiency.