Fresenius Kabi Swissbiosim GmbH & Ors v Millennium Pharmaceuticals, Inc

Facts

Four related actions in the Patents Court concerned patents belonging to Millennium Pharmaceuticals, Inc. (part of the Takeda group) protecting vedolizumab, marketed as Entyvio®, for moderately to severely active ulcerative colitis, Crohn's disease and chronic pouchitis. Fresenius Kabi Swissbiosim GmbH and Fresenius Kabi Limited, Advanz Pharma Services (UK) Limited, Accord Healthcare Limited and Samsung Bioepis UK Limited each sought revocation and/or declarations of non-infringement or Arrow relief against four 'follow-on' patents (dosing patents EP 965 and EP 834 and formulation patents EP 798 and EP 579) and two related applications, to clear the way for launching their own biosimilar vedolizumab products. The actions were commenced sequentially between February and July 2026, with trial already fixed to float from 6 April 2027; Samsung applied to join that trial. At a joint case management conference on 24 July 2026, Mr Justice Mellor was asked to resolve Millennium's proposed conditions on alignment of the claimants' invalidity pleadings and shared leading counsel, Samsung's joinder, a disclosure-related pleading dispute, and a separate confidentiality dispute between Advanz and Millennium concerning disclosure of Advanz's confidential biosimilar formulations — specifically whether Millennium's proposed in-house representatives should be subject to an extended prosecution bar covering post-grant patent amendments. This judgment records the reasons for the directions given at that hearing.

Decision

Issues

• Whether the claimants should be required to align their Grounds of Invalidity and jointly instruct leading counsel as conditions of proceeding, to protect the existing trial date.
• Whether Samsung Bioepis should be permitted to join the existing trial.
• Whether an extended prosecution bar, preventing Millennium's nominated in-house representatives from involvement in post-grant patent amendments, should be imposed to protect Advanz's confidential formulation information.

Reasoning

Mr Justice Mellor dealt first with Millennium's case management concerns. He accepted the claimants' offer to use best endeavours to align their Grounds of Invalidity by 10 September 2026 rather than imposing Millennium's more stringent conditions, noting the actions were still at an early stage, that experienced representation made further rationalisation likely, and that Millennium retained the option to return to court if alignment failed. He declined to require joint leading counsel, since he had little visibility of the emerging infringement arguments and did not wish pre-emptively to limit the claimants' options, observing that unnecessary costs might simply go unrecovered. On the central confidentiality issue, the judge applied the ten principles summarised by Floyd LJ in OnePlus v Mitsubishi, and considered the Court of Appeal's endorsement in InterDigital v OnePlus of a wide-form restriction at an early stage, particularly where the receiving party's evidence about its organisational structure is thin. He weighed Millennium's reliance on Meade J's caution in General Electric v Siemens Gamesa Renewable Energy against Advanz's reliance on Roussel Uclaf v Imperial Chemical Industries (No.2) and Merck Sharp & Dohme Ltd v GlaxoSmithKline Biologicals SA. Millennium's evidence asserted that only its two in-house lawyers, Ms Selli and Ms Cole, could give instructions on infringement, but the judge found this claim absent from their witness statements though present in prior correspondence, inferring it could not have been made under a statement of truth; he therefore found, from the size and sophistication of Takeda's organisation, that other suitably qualified personnel must exist. Rejecting Millennium's claim of severe prejudice, and noting there was no restriction on amendments proposed within these proceedings (distinguishing Merck Sharp & Dohme), the judge concluded there remained a non-negligible risk of subconscious misuse and imposed the extended prosecution bar, considering it would also protect Ms Selli and Ms Cole from difficult conflicts of interest.

Case history