Background
Fresenius Kabi, Advanz, Accord and Samsung Bioepis brought four actions seeking to clear the way for UK launches of biosimilar versions of vedolizumab, Millennium Pharmaceuticals’ anti-α4β7 antibody marketed as Entyvio®. The claims sought revocation of follow-on patents concerning dosing regimens and formulations, declarations of non-infringement and, in relation to pending patent applications, Arrow relief.
At a joint case-management conference, the principal unresolved issue concerned the conditions under which Advanz would disclose confidential details of its proposed intravenous and subcutaneous formulations. The parties agreed that two Takeda in-house representatives could enter the confidentiality club and would be barred from pre-grant claim drafting, but disputed whether the bar should also cover their involvement in post-grant claim amendments and auxiliary requests concerning vedolizumab patents in foreign proceedings and before the European Patent Office.
Takeda wished to nominate two senior in-house litigation lawyers who had central responsibility for defending and enforcing the Entyvio® patent portfolio globally. Advanz did not allege deliberate misuse, but argued that their roles created a serious risk that its confidential formulation information could subconsciously influence decisions about post-grant amendments.
The Court’s Holding
Mr Justice Mellor imposed the extended prosecution bar sought by Advanz. He found a non-negligible risk of subconscious use because the proposed representatives were intimately involved in foreign and EPO proceedings where amendments to numerous vedolizumab patents might be considered. The bar would remain relevant only while Advanz’s formulation information remained confidential and would not prevent Takeda from proposing amendments in the UK proceedings.
The Court rejected Takeda’s contention that the restriction would cause material prejudice or require an impractical reorganisation. Takeda’s evidence did not establish that only its two preferred representatives could provide instructions on infringement. Given Takeda’s size, resources and the importance of vedolizumab to its business, the Court found that other suitably qualified personnel were available and could be nominated if the two preferred representatives wished to continue their global patent roles.
On other case-management issues, the Court allowed Samsung Bioepis to join the April 2027 trial. It accepted the claimants’ undertaking to use best endeavours to align their invalidity cases rather than immediately requiring a single consolidated pleading or shared leading counsel, and declined at that stage to strike out a challenged part of Fresenius’s invalidity pleading.
Key Takeaways
- A UK prosecution bar is not routine, but may be ordered where case-specific evidence shows a meaningful risk that confidential information could influence patent prosecution or post-grant amendment decisions.
- The risk of subconscious misuse can justify restrictions even without any allegation that the receiving individuals would deliberately breach confidentiality.
- A large receiving party must provide persuasive evidence if it claims that only particular employees can give instructions; organisational size and the availability of alternative personnel are relevant to proportionality.
Why It Matters
The decision illustrates how the Patents Court balances a party’s need for access to confidential product information against the owner’s interest in preventing that information from shaping related patent claims abroad. It also confirms that post-grant amendments can present a genuine confidentiality concern despite rules prohibiting added matter or an extension of patent protection.
For pharmaceutical patent litigation involving confidential biosimilar formulations and coordinated international portfolios, companies may need to separate personnel handling infringement instructions from those directing foreign oppositions, enforcement and claim amendments.