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Illumina and Sequenom (the “Claimants”) have been successful in another action relating to their prenatal diagnostics patent portfolio, with Mr Justice Arnold finding that Sequenom’s patent EP 1 524 321 (the “Patent”; Illumina being the exclusive licensee) was valid and infringed by TDL’s product, the Harmony Test which was developed by Ariosa (who accepted joint liability for any infringement by TDL, together the “Defendants”).

The parties had been involved in previous litigation in 2017 in relation to five other patents covering prenatal diagnosis (see previous blog post here).

Foreign Language Experts
The sole prior art document in this case, “Ikeda”, was a Japanese abstract and there was a dispute between the parties as to how one word was to be translated. Arnold J found that what mattered was how the English translation would be understood by the skilled person, who is located in the United Kingdom. In this case the exact translation of the word had little relevance to the interpretation of Ikeda, although Arnold J took the opportunity to issue a reminder that translation is a form of expert evidence which requires the permission of the court and the production of formal expert reports. Where translations are agreed it is common for parties to rely on them without any formal order of the court, but where a dispute arises these requirements must be complied with.

Claim 1 is a product-by-process claim as follows:
“A fraction of a sample of the blood plasma or serum of a pregnant woman in which, as the result of said sample having been submitted to a DNA extraction, followed by a size separation, of the extracellular DNA, the extracellular DNA present therein substantially consists of DNA consisting of 500 base pairs or less”

There were three issues in dispute on construction and Arnold J agreed with the Claimants on each of these. First, the claim would not be taken to be limited to circulatory extracellular DNA. Secondly, the claim did not require an enrichment of foetal DNA by at least 2.0-fold, as contended by the Defendants. Thirdly, the claim did not cover a fraction derived from a sample that which did not originally contain any DNA of greater than 500 base pairs; there can only be a size separation if there is something to separate.

Obviousness Over Ikeda
The substantial dispute between the parties was what Ikeda disclosed to the skilled person, with the Defendants contending that it disclosed the fact that foetal DNA fragments in maternal plasma are shorter on average than maternal DNA fragments and the Claimants disputing this. After considering the expert evidence, Arnold J agreed with the Claimants that the skilled reader (without being influenced by hindsight, which was a criticism of the Defendants’ expert) would think that Ikeda was drawing a contrast between short foetal DNA fragments and longer foetal DNA fragments.

This finding was essentially determinative of the issues of obviousness, with neither party disputing that if the other party’s interpretation was correct then the other party would succeed.

Arnold J noted that while the prior art would be read with care and interest, the skilled person does not assume that the document they are reading has any relevance to the problem the skilled person is addressing. Ikeda had been subjected to sustained, detailed and high-powered forensic analysis during the case, but that is not how it would have been read by the skilled person. Arnold J agreed with the Claimants that the skilled person would take Ikeda at face value, but even if they had performed a deeper analysis, they would have still concluded it was all about the size distribution of foetal DNA and would not render the Patent obvious.

Arnold J reviewed the reasoning of the Court of Appeal in Regeneron v Kymab and concluded that the Patent was not insufficient. The claims were not broader than justified by the technical contribution as the Patent disclosed a general principle of technical utility. The Defendants argued that the excessive claim breadth was evident from the fact that there would be cases in which the invention had hardly any effect and the Claimants accepted that there could be such cases, but they would be very rare. Arnold J noted that his finding on the third construction issue meant the claim did not cover fractions obtained from samples that would result in such cases but, even it did cover such samples, the fact that on very rare occasions the invention is of no practical benefit does not detract from the fact that in the vast majority of cases it is of technical utility.

The Defendants contended that the inventions were excluded from patentability under s1(2)(a) of the 1977 Act on the ground that they are discoveries. The Defendants accepted that as the law currently stands this case could not succeed, but asked Arnold J to make certain findings of fact to enable the point of law to be argued in a higher court if necessary. Arnold J declined to do so, stating that it is unsatisfactory for the court to make findings of fact outside of a legal context.

On infringement, the only issue was the 2.0-fold enrichment construction argued by the Defendants, which had been rejected by Arnold J. As he had construed the claim, TDL’s product infringed it.

A copy of the decision can be read here.

Headnote: Elsa Glauert and Amy Crouch, Simmons & Simmons LLP