The High Court has issued a noteworthy decision in Merck KGaA v Merck Sharp & Dohme LLC [2026] EWHC 1113 (Ch) clarifying the relationship between contractual confidentiality obligations, CPR 31.22, which governs the use of documents disclosed in civil proceedings, and the principle of open justice.

The judgment provides important guidance for parties seeking to use disclosed documents outside the proceedings in which they were disclosed. It confirms that contractual confidentiality obligations may limit their use, even where the documents were referred to in open court.

Procedural history

This decision arises out of the long-running dispute between two pharmaceutical giants: Merck KGaA (the German business – “Merck Global“) and Merck, Sharp & Dohme (the US business – “Merck US“), which were once part of the same company. The substantive trade mark issues were resolved in earlier proceedings, culminating in a public damages judgment (see our recent blog on the most recent decisions). The present application concerned the post-trial use of documents disclosed during the main litigation.

Following the conclusion of the litigation, Merck Global sought to maintain restrictions over a set of 91 ‘Confidential Documents’, including internal strategy papers, transfer pricing material, board minutes and licensing agreements. Merck US, by contrast, argued that it should be free to use those materials for collateral purposes, including potential use in ongoing litigation in other jurisdictions, particularly where those documents had been referred to during the public trial.

The decision

The court sided largely with Merck Global. It refused Merck US’s attempt to obtain a wholesale release from confidentiality obligations, and granted an order that preserved confidentiality over the disputed documents, “but making clear that [Merck US] may in future, but with some limit of time or purpose …, make an application to use one or more of the Confidential Documents if it can be justified by reference to a special circumstance constituting a good reason which would include identifying a particular use for [Merck US]’s purposes”.

The court also held that use of documents in foreign litigation did not engage open justice principles, and so should be pursued through the Evidence (Proceedings in Other Jurisdictions) Act 1975, rather than via CPR 31.22.

The court’s reasoning

1. The legal framework

The court’s analysis centred around three key elements:

CPR 31.22, which restricts collateral use of disclosed documents, subject to certain exceptions¹;
The confidentiality club agreement between Merck Global and Merck US, under which Merck US had contractually agreed not to use the documents beyond the proceedings and which contained no mechanism for Merck US to challenge Merck Global’s designation of documents as confidential; and
The principle of open justice, which supports public access to materials necessary to understand judicial decisions.

Ordinarily, where documents are read or referred to in open court, they may lose protection from collateral use. However, that principle is not immoveable and the presence of a contractual confidentiality regime altered that position.

2. Open justice has limits

The court confirmed that open justice is the default position. The purposes of open justice, as set out by the Supreme Court in Dring v Cape Intermediate Holdings [2019] UKSC 38, are “to enable public scrutiny of the way in which the courts decide cases … and to enable the public to understand how the justice system works and why decisions were taken”.

However, open justice is not an immoveable rule.

The Court of Appeal in JC Bamford v Manitou [2023] EWCA Civ 840 held that “[w]here it is necessary to protect trade secrets, however, open justice must give way to a still greater principle, which is justice itself”, and that “[e]ven lower grade confidential information is entitled to protection where its publication is not necessary for open justice”.

In this case, the court concluded that:

The underlying damages judgment was fully public and understandable (to the public as well as to the parties) without access to the confidential material.
The documents in issue contained commercially sensitive information, including internal strategy and pricing materials.
The public could still understand how the court reached its conclusions without access to the underlying confidential documents.
Nothing would prevent a member of the public wishing to access documents for open justice purposes from making an application to the court to do so.

3. The importance of the contractual framework

A critical aspect of the judgment is the court’s emphasis on the parties’ contractual framework. The confidentiality agreement imposed an obligation on Merck US not to use the documents outside the proceedings, and that obligation was not displaced merely because documents were deployed at trial. Furthermore, Merck US had also agreed to accept Merck Global’s designations of confidentiality with no contractual mechanism to challenge designations of confidentiality. In effect, Merck US had “contracted out” of its ability to rely on the ordinary CPR 31.22 position, at least without further application to the court (which it had not made).

Furthermore, the application of the principle of open justice “must be assessed in the context of the contractual regime agreed between the parties”. As a result, the court found that open justice did not require lifting the contractual confidentiality protections.

A shift in the practical burden

A notable feature of the decision is the court’s approach to burden. The usual position is that the party asserting confidentiality must explain why the material should remain protected. However, given Merck US’s contractual obligation not to use the documents outside the proceedings and not to challenge their designated confidentiality, the court held that it was for Merck US to show “either that there is an open justice reason why a particular document or documents needs to be made available or that there are “special circumstances” constituting a “good reason” why it should be released from its contractual obligations and be free to use that document or documents for an identified proposed collateral use”.

The court therefore rejected Merck US’s attempt to obtain a wholesale release from confidentiality obligations. Instead, any use of the documents would need to be justified on a targeted basis by reference to specific documents and a clearly defined proposed use.

What does this mean in practice?

This case underlines the importance of thinking ahead at the disclosure stage.

Parties entering into confidentiality arrangements should assume those obligations may outlive the proceedings.
Any party seeking to re-use disclosed documents should be prepared to make focused, evidence-based applications, rather than relying on general open justice arguments.
Applications to use disclosed confidential documents in foreign proceedings must be made under the Evidence (Proceedings in Other Jurisdictions) Act 1975.
The case reinforces the English courts’ willingness to protect commercially sensitive information.

This latest Merck v Merck judgment is a reminder that while open justice remains a cornerstone of English litigation, it is not absolute and may yield where confidentiality and contractual obligations demand it.

Key Takeaways

Confidentiality agreements carry significant weight: parties should expect courts to enforce agreed confidentiality regimes strictly, even post-trial.
Use of documents at trial is not determinative: documents do not automatically lose protection when referred to in open court, especially if contractual restrictions remain in place.
Open justice is nuanced: the court will consider whether access to specific documents is necessary to enable the public to scrutinise a decision.
Broad attempts to lift confidentiality restrictions are unlikely to succeed; applicants must identify specific documents and purposes and justifications for their use.
Foreign litigation is not an open justice argument: use of English disclosure documents in overseas proceedings requires separate justification and use of appropriate procedural routes.

With thanks to Jennifer Bryant, Senior Professional Support Lawyer, and Fabienne Cuthbert, trainee solicitor, for co-authoring this article.

Footnote

¹ CPR rule 31.22:

(1) A party to whom a document has been disclosed may use the document only for the purpose of the proceedings in which it is disclosed, except where –

(a) the document has been read to or by the court, or referred to, at a hearing which has been held in public;

(b) the court gives permission; or

(c) the party who disclosed the document and the person to whom the document belongs agree.

(2) The court may make an order restricting or prohibiting the use of a document which has been disclosed, even where the document has been read to or by the court, or referred to, at a hearing which has been held in public.

(3) An application for such an order may be made –

(a) by a party; or

(b) by any person to whom the document belongs.

[…]