Patents Court imposes extended prosecution bar in Fresenius Kabi v Millennium Pharmaceuticals

The Patents Court has imposed an extended prosecution bar preventing two senior in-house lawyers at Takeda subsidiary Millennium Pharmaceuticals from being involved in post-grant patent amendments concerning vedolizumab, after finding the company had failed to establish that no other personnel could perform the role.

Mr Justice Mellor handed down the judgement following a joint case management conference in four related actions brought by Fresenius Kabi, Advanz Pharma, Accord Healthcare and Samsung Bioepis, each seeking to clear the way for their own biosimilar versions of Millennium's anti-α4β7 antibody Entyvio, marketed for inflammatory bowel conditions including ulcerative colitis and Crohn's disease. The claims target a cluster of so-called follow-on patents covering dosing regimens and formulations, all sharing a 2012 filing date, after the original protection for vedolizumab itself expired.

Having resolved most procedural matters at the hearing, including directing Samsung to join the existing trial listed for 2027 and declining to impose stricter alignment requirements on the claimants' invalidity cases, the judge focused his written reasons on a single disputed issue in the Advanz proceedings: the scope of a prosecution bar governing Millennium's access to Advanz's confidential formulation details.

The parties had agreed that two Takeda in-house lawyers, Ms Selli and Ms Cole, could join the confidentiality club and would be barred from involvement in pre-grant claim drafting. The dispute was whether that bar should extend to post-grant amendments and auxiliary requests across foreign jurisdictions and the European Patent Office, a protection Advanz sought given the individuals' central roles in Takeda's global vedolizumab patent strategy.

Applying the ten-point framework established by Floyd LJ in OnePlus v Mitsubishi Electric, together with the Court of Appeal's guidance in InterDigital v OnePlus and earlier authority in Roussel Uclaf v Imperial Chemical Industries, the judge accepted that Advanz was not alleging deliberate misuse but rather the practical difficulty of excluding confidential information from consideration when advising on claim amendments that might narrow protection to exclude a rival's formulation. He noted the particular difficulty facing individuals asked to comment, or decline to comment, on whether a proposed amendment made a difference, when either response risked revealing the very information meant to remain confidential.

Millennium argued the restriction would be disproportionate given the relatively short period before Advanz's formulation details became public through US regulatory filings, and that Ms Selli and Ms Cole were the only individuals within the organisation capable of instructing lawyers on infringement issues. The judge rejected this account, drawing a pointed inference from the evidence itself. A letter from Millennium's solicitors had asserted no other personnel could perform the role, yet that specific assertion was conspicuously absent from two rounds of witness statements sworn by Millennium's own solicitor, despite covering substantially similar ground. The judge concluded this omission could not have been accidental and inferred it reflected an assertion that could not properly be made under a statement of truth, particularly given Takeda's scale as an organisation employing around 50,000 people.

Finding no material prejudice would result from the extended bar, and that Takeda retained the option of nominating alternative qualified personnel to handle instructions on infringement, the judge ordered the wider restriction. He observed that the bar would in practice benefit Ms Selli and Ms Cole by removing them from situations where they would otherwise struggle to separate confidential knowledge from their ordinary prosecution duties across Millennium's substantial vedolizumab patent portfolio.