Safestand v Weston [2023] EWHC 1098 (Pat)

10 May 2023

Henry Edwards successfully represented the Claimant in its application for specific disclosure of documents and data relating to experiments relied on in the Defendants’ Amended Notice of Experiment (“ANOE”)—also known as Mayne Pharma disclosure.

The context of the hearing was a claim for infringement of three patents, including on the doctrine of equivalents, and three re-registered design rights of the Claimant. The Defendants have claimed for revocation of the patents and re-registered design rights, and have pleaded a Formstein defence and non-infringement of each patent. Two of the asserted patents (the “Trestle Patents”) were relevant to the application and relate to trestles for supporting workman platforms used on building sites. It is alleged that the Defendant’s working platform system, including two different sets of framed components, the “Standard Main Frame KKS” and a shorter “KK 650,” infringe the Trestle Patents. A key issue is whether these framed components are “trestles” within the meaning of the Patents.

The Claimant argued that the Defendants’ deployment of the ANOE in aid of its non-infringement case for the Standard Main Frame KKS was a partial disclosure of part of a body of experimental data. This partial disclosure gave rise to an implicit or consequential waiver of privilege in a series of other undeployed experiments using the same methodology.

After reviewing the legal principles underlying legal privilege, waiver of privilege and disclosure relating to experiments in patent cases, Mr Campbell Forsyth (sitting as a Deputy Judge of the High Court) found that the Defendants’ construction of ‘trestle’ in terms of longitudinal stability was implicitly reliant at least in part on the results of the deployed experiments. These were relied upon to demonstrate that there was a consistent difference in performance characteristics between the Defendants’ frames and conventional trestles that supported their construction. Therefore, the judge held that the Defendants’ deployment of the ANOE was an implicit or consequential waiver of privilege in any experiment dealing with the relative longitudinal stability of the main frames and a trestle made based on aspects of the Trestle Patents. This was because the results of those other experiments were needed to understand the deployed experiments in their proper context, including whether this difference in performance characteristics was consistently apparent in the results.

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