Background
Janssen-Cilag Limited, a Johnson & Johnson subsidiary, holds the UK marketing authorisation for Carvykti, an innovative CAR-T cell therapy for relapsed or refractory multiple myeloma. The United States of America, acting through the Department of Health and Human Services, is the registered proprietor of European Patent (UK) 3,689,383 B1, covering chimeric antigen receptors targeting B cell maturation antigen. A licensee of that patent, 2seventy bio (a Bristol Myers Squibb subsidiary), launched UPC infringement proceedings against J&J in January 2026 in respect of Carvykti, asserting that it falls within the scope of the patent. In parallel, 2seventy markets a competing product, Abecma, under the same licence.
Faced with the threat of infringement proceedings in both the UPC and the UK, J&J issued a claim for revocation of the patent in the UK Patents Court on 5 February 2026. Because the patent proprietor is a foreign sovereign state, service raised difficult questions under the State Immunity Act 1978 (SIA). J&J initially obtained orders from HHJ Hacon permitting alternative service on the basis that revocation was “an action in rem” within s.12(7) SIA, exempting it from the mandatory diplomatic service channel prescribed by s.12(1). After discovering that the NIH had instructed German patent attorneys Grünecker to file a London address for service (AFS) at the UKIPO, J&J also served the proceedings there. The USA applied to set aside service and challenge jurisdiction.
The application raised two distinct questions: first, whether service at the UKIPO-registered AFS constituted service in a manner “agreed” by the state under s.12(6) SIA, disapplying the mandatory diplomatic channel; and second, whether a patent revocation action is properly characterised as “an action in rem” under s.12(7) SIA, so that s.12(1) never applied in the first place. Both issues were argued before Mr Justice Mellor on 5 June 2026.
The Court’s Holding
On the s.12(6) question, Mellor J held that the USA was validly served when proceedings were delivered, on 23 March 2026, to the Grünecker UK address filed on the UKIPO Patents Register. The court rejected the USA’s argument that the AFS had been provided only for the limited administrative purpose of validating the European patent in the UK. That argument was factually wrong: the EP(UK) had already been granted before the AFS was filed, and s.77(1) of the Patents Act 1977 confers automatic rights upon grant without any requirement to file a UK address. The UKIPO’s own Manual of Patent Practice confirms that filing an AFS is entirely voluntary. The USA therefore elected to provide the address, and viewed objectively, that election carried the purpose which CPR 63.14 attaches to a registered AFS — permitting service of claims relating to the registered right.
The court further held that s.12(6) imposes no formal requirements on the form of agreement; agreement may arise from writing, speech, or conduct, including a state’s unilateral proclamation to the world of a mechanism by which it can be reached, provided that proclamation is clearly directed at proceedings in foreign courts. On the separate “no authority” point raised by the USA — namely that the NIH lacked authority under US law to waive the USA’s procedural immunities — the judgment addresses that contention in the full written reasons. The court also ruled on the s.12(7) “action in rem” issue at the USA’s request, so that the analysis would be available if relied upon in future proceedings.
Key Takeaways
- A foreign state that voluntarily files an address for service at the UKIPO without restriction may be held to have “agreed” to service at that address within the meaning of s.12(6) SIA 1978, bypassing the mandatory diplomatic channel in s.12(1).
- Providing a UK address for service is not required for validation of a European patent (UK); it is an elective step, and a state’s voluntary, unrestricted filing is assessed objectively and extends to service of revocation proceedings under CPR 63.14.
- Where s.12(6) applies, the two-month response period in s.12(2) and the default-judgment restriction in s.12(4) do not apply — claimants must account for this when planning case timelines.
- The SIA’s mandatory diplomatic service route in s.12(1) cannot be bypassed by CPR 6.15 alternative service orders where it applies; the court confirmed courts have no discretion to dispense with that statutory requirement.
Why It Matters
This decision is significant for intellectual property litigants facing a scenario in which a foreign sovereign state holds a patent that threatens their commercial freedom to operate. The judgment establishes that a state which actively manages its patent portfolio in the UK — filing an address for service at the UKIPO and coordinating with licensees in related proceedings — may be treated as having agreed to service in a manner that avoids the lengthy delays inherent in diplomatic service through the Foreign, Commonwealth and Development Office. For pharmaceutical and biotech companies contesting government-owned patents, the ruling offers a practical pathway to litigate promptly.
More broadly, the case illustrates the growing intersection between state immunity doctrine and modern IP litigation, particularly as government agencies in the United States and elsewhere increasingly hold commercially valuable life-sciences patents. The court’s analysis of s.12(6) clarifies that agreement to service need not be express or formal, and that a state’s own conduct — including voluntary registration steps and active participation in related foreign proceedings — will be weighed objectively. Practitioners advising sovereign patent-holders on portfolio management in the UK should treat the filing of an unrestricted AFS with the UKIPO as carrying material procedural consequences.