As in other Common Law jurisdictions, one of the distinguishing characteristics of litigation in England and Wales as compared to its Civil Law (or "continental") counterparts is the availability of document disclosure. Referred to as "document discovery" in US procedure, this is the requirement on one party to litigation to provide to the other the documents and materials in its possession that are (or may be) relevant to the case.

So, a party to English proceedings can gain access to relevant documents of its opponent in a manner-un-available to parties to litigation in continental (Civil Law) European countries. The downside, however, is the cost and time for each party to search for and review potentially relevant documents for disclosure. With the increase in the capacity of document storage technologies and the sheer volume of electronic documents generated and retained on a daily basis in modern commercial life, this task becomes ever more challenging. And costly.

English patent litigation procedure has long been ahead of the rules governing other (non-patent) English litigation in tackling the burden of disclosure while seeking to preserve its advantages. An alleged infringer, for example, can avoid altogether the need to disclose documents relating to the allegedly infringing product or process. To do so they can instead opt to provide a description of the product or process in sufficient detail to enable the court to determine the issue of infringement. This Product / Process Description (PPD) is signed by someone having knowledge of the matters it describes and who can, if necessary, be cross-examined in court on any points of contention or doubt.

The use of PPDs makes English procedure (and the UK as a forum for patent litigation)  attractive from the point of view of proving infringement. A case can be started on a good faith belief in infringement inferred or evident from publicly available information. This avoids the need to engage in uncertain pre-action seizures or costly testing or reverse engineering. Provision of the PPD then provides clarity as to the factual position, leaving legal arguments for and against infringement to proceed on a sound footing.

English patent litigation procedure also limits disclosure on the validity side. For example,  no disclosure is required of documents relevant to validity that fall outside a four year window: two years either side of the contested patent's priority date.

But even the requirement for validity disclosure falling within a four year period often still involves an onerous search and review task for patentees. And in many cases documents produced often yield only minimal, if any, assistance to the Court for resolution of the validity dispute. However, case management decisions in two recent High Court patent cases interpreting some 2013 changes to the Civil Procedure Rules have improved the situation significantly by deciding that whilst disclosure should be available as regards validity in appropriate cases, it is not an automatic right: it must be justified in terms of cost and probative value.

The first case was Positec Power Too​ls (Europe) and others v Husqvarna [2016] EWHC 1061 (Pat), decided in May this year. The issue to be decided was what disclosure was required by a patentee where the obviousness of its patent was in issue. Importantly the case was heard by Mr Justice Birss, whose attitude to case management is strongly influenced by his time in the procedurally streamlined Intellectual Property Enterprise Court or IPEC (the UK's IP jurisdiction for technically straightforward and lower value cases). IPEC has a very pragmatic attitude to disclosure, giving the judge broad discretion as to how much, if any, disclosure is appropriate. Positec makes it clear that this approach is now also appropriate in the main court for patent disputes being the High Court (Patents Court). Birss J confirmed that the Court will readily consider ordering disclosure on an issue-by-issue approach on validity rather than defaulting to an all-embracing "standard" disclosure order for validity. And, where requested, it is clear that the Court will scrutinise very carefully the need for disclosure on this issue-by-issue basis.

Birss J ruled that for disclosure to be appropriate it must be justified by weighing up the likely probative value of documents disclosed against the cost and time involved in providing the relevant disclosure.  In a case involving a straightforward claim of obviousness (as in Positec) it is unlikely that disclosure on this issue would add much: what was actually done by the inventor is of much less interest than what the notional skilled addressee of the patent would have done, which is a matter for expert evidence. There are circumstances where this could be different, however: disclosure may well be appropriate if the patentee itself is relying on the commercial success of the alleged invention or the reactions of others to it to support a case of inventive step. Similarly, if the inventor is to be called as a witness or other internal documents are to be relied upon, then disclosure of all documents relevant to the issue will be appropriate. This would provide context and avoids cherry-picking by the patentee. The key in all disclosure applications, is that provision of disclosure is within the judge's discretion based on the balance of probative value and cost.

The second recent case of interest in this area is Illumina and others v Premaitha Health [2016] EWHC 1516 (Pat). In a case management hearing in that case, the alleged infringer sought disclosure from the patentee on the issue of sufficiency. The Judge, Carr J, followed the decision in Positec and reiterated the principles set out by Birss J. The request was denied on the basis that disclosure would be very costly and the fruits of disclosure would not add much to the case. Again, it was made clear that if (but only if) justified, disclosure is available: for example if the patentee advanced a defence to a claim of insufficiency that the inventor had no difficulty in practising the invention, then disclosure would be appropriate. However, that defence was not advanced in Illumina and so the request for a disclosure was denied.

The Court's approach to disclosure to validity issues represented by these cases, combined with the availability of PPDs highlights the attractiveness of the UK as a forum for litigation in patent cases. The flexibility of the judges' approach means that unnecessary costly validity disclosure is eradicated, while remaining available when the issues and the interests of justice demand. the requirement of defendants to provide PPDs / infringement disclosure remains. This is welcome news both for those bringing and those defending patent proceedings.

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