Later evidence may be relied on in patent validity disputes -- but only just

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 [2013] 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.

Yeda

Yeda and Teva were the registered proprietor and exclusive licensee of a patent relating to a synthetic copolymer, copolymer-1. Teva marketed a copolymer-1 product under the brand name Copaxone for the treatment of relapsing-remitting multiple sclerosis (MS). The patent itself described copolymer-1 as a mixture of polypeptides composed of alanine, glutamic acid, lysine and tyrosine in a molar ratio of approximately 6:2:5:1, and the specification clearly stated that the invention consisted of the compositions themselves, their use in the treatment of MS and a method for making copolymer-1. Mylan, which planned to launch a product to competed with Copaxone, challenged the validity of the patent for obviousness over a prior publication ('Johnson') and for lack of a technical contribution. It appeared that, while the results of the Johnson phase III trial were not published in a scientific paper until after the priority date of Yeda's patent, the results of the trial had been announced beforehand. Mylan said that, even if Yeda's patent was not invalid, Mylan's proposed product did not infringe the claims of the patent on its proper construction because its own copolymer didn't confirm to the claimed ratio of amino acids and that, if the patent was not construed as Mylan argued it should be, it was in any event insufficient.

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.

Yoda

* Arnold J was not correct to hold that, if Yeda's patent specification made a technical effect plausible, it was not open to Mylan to mount a challenge to the existence of that effect by the use of later evidence. The problem-solution approach to inventive step required the court to judge inventiveness by reference to what it was that the invention brought with it, this being its technical effect or advance. In doing so, the court was not judging the obviousness of the claimed invention by reference to later evidence: it was simply defining by evidence what it was that the invention was or brought with it [Says the IPKat, this is a fine difference but clearly a significant one. However, by allowing for reference to be made to later evidence, the Court of Appeal is also confining its scope of applicability within narrow straits].

* 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.

Yada

* Turning to infringement, the correct question to ask was whether the percentage difference from 6:2:5:1, expressed as a molar fraction in any given sample, was within the variability which could arise from amino acid analysis and copolymer-1 synthesis. The skilled person would not consider a difference which exceeded such variability as being within the scope of the claim. Mylan's product differed from a product with a 6:2:5:1  ratio principally in that the molar fraction of tyrosine was 29.6 % greater. There was no evidence that this variation was greater than that which could occur from amino acid analysis and copolymer-1 synthesis. Accordingly, Mylan failed to show that its product did not infringe.