Summary
Privilege in material relating to litigation experiments should be treated as waived only to the extent necessary to prevent unfairness or selective deployment. In ordinary cases, disclosure under Mayne Pharma Pty Ltd v Debiopharm SA is confined to preliminary investigation leading to the particular experiment deployed, not every earlier or related experiment.
Where experiments are complex, the court should consider issue-specific information, focused requests, expert questions and other proportionate measures instead of automatically ordering standard disclosure. Disclosure of confidential trade secrets to experts or laboratories is permissible only where reasonably necessary to address a serious issue, protected by adequate confidentiality arrangements and consistent with the overriding objective.
Factual background
The claimant alleged infringement of a patent concerning the production of zirconium-cerium-based mixed oxides. The applications arose before trial after earlier case-management orders concerning experimental evidence, disclosure, inspection of the defendants’ manufacturing process, confidential samples and a confidentiality club.
The first application concerned whether the claimant had complied with an order requiring disclosure of documents directly associated with or underlying experimental evidence, including potentially privileged material. The defendants sought further material concerning earlier experiments, legal advice and draft expert reports.
The second application concerned testing samples taken during an inspection of the manufacturing process and admitting a further expert to the inner confidentiality club. The central issues were the scope of implied waiver, proportionality of disclosure, the probative value of proposed testing and the protection of confidential process information.
Held
- Application 1. The claimant had provided sufficient information at that stage. Although the material was not supplied precisely in the form required by the earlier order, the narrative evidence and exhibits were an adequate practical alternative. No general declaration of compliance was made, but the court declared that no further disclosure should be given at that stage.
- The court distinguished between waiver of privilege and the separate question whether further disclosure was necessary or proportionate. Implied or consequential waiver must be determined specifically by reference to the material deployed, the purpose of deployment and the risk of unfairness or misunderstanding. Deployment does not open a general class of related privileged documents.
- In complex patent experiments, Mayne Pharma Pty Ltd v Debiopharm SA requires disclosure of preliminary investigation leading to the particular experiment deployed. It does not generally extend to earlier experiments on different products, legal advice concerning experimental validity or draft expert reports. Clearer cases may justify wider disclosure, including inevitable-result cases and cases concerning completeness or variation in experimental data.
- The court should use the range of procedural tools available under the CPR. Standard disclosure is one option, not an automatic default. Issue-specific information, focused requests, specific disclosure and proportionate questions to experts may provide a fairer and less costly means of testing experimental evidence.
- Application 2. Testing of starting materials and finished-product samples was permitted on the agreed basis. No order was made for testing of the disputed intermediate samples or disclosure of confidential calcination conditions, although permission to reapply was preserved. The proposed testing was not shown to have sufficient incremental probative value and would create unnecessary risks to trade secrets.
- Permission was granted to admit Professor Hardacre to the inner confidentiality club on the proposed narrower terms. Disclosure of confidential information to a third party requires reasonable necessity to address a serious issue, adequate protection against unauthorised disclosure and consistency with the overriding objective. The balance marginally favoured admission because suitable expert evidence on equivalence was reasonably necessary and the proposed risk was low.
The court’s approach to earlier authorities
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Appellate history
First-instance decision of the High Court (Patents Court). The judgment records earlier case-management orders by Birss J and Arnold J in the same proceedings, but no appeal from this decision.
Key cases cited
20 authorities cited.
- Three Rivers District Council and others (Respondents) v. Governor and Company of the Bank of England (Appellants) (2004) [2004] UKHL 48
- Regina v Special Commissioner and another, Ex p Morgan Grenfell & Co Ltd [2002] UKHL 21
- R v Derby Magistrates' Court, Ex parte B [1995] UKHL 18
- Lucas v Barking, Havering & Redbridge Hospitals NHS Trust [2003] EWCA Civ 1102
- Dunlop Slazenger International Ltd v Joe Bloggs Sports Ltd [2003] EWCA Civ 901
- Paragon Finance Plc (formerly National Home Loans Corpn Plc) v Freshfields [1999] 1 WLR 1183
- Positec Power Tools (Europe) Ltd & Ors v Husqvarna AB [2016] EWHC 1061 (Pat)
- Smith & Nephew Plc v Convatec Technologies Inc & Anor [2014] EWHC 146 (Pat)
- IPCom GmbH & Co Kg v HTC Europe Co Ltd & Ors [2013] EWHC 52 (Pat)
- BSW Ltd v Balltec Ltd [2006] EWHC 822 (Ch)
- Mayne Pharma Pty Ltd & Anor v Debiopharm SA & Anor [2006] EWHC 164 (Pat)
- Fulham Leisure Holdings Ltd v Nicholson Graham & Jones [2006] EWHC 158
- R v Secretary of State for Transport, Ex p. Factortame [1997] EWHC 445 (Admin)
- Electrolux Northern v Black & Decker [1996] FSR 595
- Honeywell Ltd v Appliance Components Ltd unreported, 22 February 1996
- Nea Karteria Maritime Co v Atlantic & Great Lakes Steamship Corporation [1991] Com LR 138
- Roussel Uclaf v ICI [1990] RPC 45
- Warner-Lambert Co v Glaxo Laboratories Ltd [1975] RPC 354
- Nichia Corporation v Argos Ltd
- Actavis v Lilly
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Cases citing this case
3 later cases · 2 positive · 1 negative
Most senior citing decisions:
- Merck Sharp & Dohme (UK) Limited v Halozyme, Inc [2026] EWHC 1838 (Pat) applied
- SafeStand Limited v Weston Homes PLC & Ors. [2023] EWHC 1098 (Pat) applied
- Jonathan Paul Thielmann & Ors. v Galina Besharova [2022] EWHC 2879 (Ch) doubted
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