Irides: Weekly global patent litigation update

This edition features updates from: The USA, Netherlands, the UK and the Unified Patent Court (UPC).

The Irides Weekly Update is our round-up of patent litigation news highlights from around the world.
 

USA

Court of Appeal adopts narrow approach to claim construction clarifying the importance of clear claim language.
[Satius v Samsung Electronics 2025-1446] 

On 1 October 2026, the Court of Appeals for the Federal Circuit (CAFC) in Satius Holding, LLC v Samsung Electronics Co., Ltd. addressed the scope and construction of patent claims covering a communications apparatus for transmitting “electric or electromagnetic signals over air”. The Court rejected Satius’s proposed interpretation that the claims should be understood as requiring the conversion of electric signals into electromagnetic signals before transmission. Instead, applying the claim language as written, the Court held that the claims encompassed two alternatives: transmitting signals over air in electric form or in electromagnetic form.

The Court emphasised that transmitting signals “over” the air was not the same as transmitting signals “to” the air. Satius’s construction would have required an electric signal to be transformed into an electromagnetic signal before transmission, but no such transformation step appeared in the claim. The CAFC acknowledged that although Courts generally seek to avoid constructions producing nonsensical results, they cannot redraft claims to make them operable or preserve their validity. Where a claim is susceptible to only one reasonable construction, it must be construed in accordance with the language chosen by the patentee.

The CAFC nevertheless disagreed with the District Court’s conclusion that the claims were indefinite. In the CAFC’s view, scientific impossibility did not necessarily create uncertainty about claim scope. The claims clearly covered the transmission of electric signals over air, even though the parties agreed that this was scientifically impossible. The relevant question for definiteness was whether the claims informed the skilled person with reasonable certainty about the scope of the invention, rather than whether every embodiment within that scope was operable.

That distinction did not save the patent. The CAFC affirmed the judgment that claims 1, 11 and 18 were invalid, but did so for lack of enablement under 35 U.S.C. § 112(a), rather than indefiniteness under 35 U.S.C. § 112(b). The specification was required to enable the full scope of the claimed invention. As one of the two expressly claimed alternatives was scientifically impossible, a skilled person could not make and use the invention across its full scope. The Court therefore considered the enablement requirement to not be satisfied.
 

Netherlands

The Hague District Court upholds Halozyme patent and grants cross-border injunction against MSD’s Keytruda SC. 
[Merck Sharp Dohme v Halozyme C/09/695432 / HA ZA 25-1075).

In Merck Sharp Dohme v Halozyme, the District Court of The Hague has upheld the validity of Halozyme’s patent EP 2 797 622 (EP 622) and found it infringed by Merck Sharp Dohme's (MSD’s) subcutaneous Keytruda product, the Court granting relief extending beyond the Netherlands to Belgium, Denmark, France, Ireland, Italy, Sweden and Switzerland.

EP 622 concerns hyaluronidase in the form of modified PH20 polypeptides with increased stability in the presence of phenolic preservatives, useful in subcutaneous antibody formulations. The Court characterised claim 1 as a product claim with functional characteristics and rejected MSD’s arguments on claim construction, particularly in relation to the demonstration of increased phenol stability.

The Court also rejected each of MSD’s validity attacks. On sufficiency, although it found that testing might be laborious or time consuming, that did not amount to an undue burden and the patent identified positions relevant to phenol stability and provided examples enabling the skilled person to produce and test suitable PH20 variants. MSD’s novelty case failed as the Court construed a “modified PH20 polypeptide” in EP 622 as not being a naturally occurring polypeptide and all the PH20 polypeptides in the prior art relied on for novelty were naturally occurring. As to inventive step, the Court held that none of MSD’s cited prior art provided the skilled person with a reason to make amino acid modifications at the claimed positions to improve the phenol stability of PH20, still less with a reasonable expectation of success. The added matter attacks on claim 1 and the dependent claims were also unsuccessful.

Turning to infringement, ALT-B4, the PH20 enzyme used in MSD’s subcutaneous formulation, contained a number of changes to the amino acid sequence, including those specified by the claim. The Court held that the fact that there were additional modifications did not take ALT-B4 outside claim 1, which did not restrict the total number of substitutions or prevent modifications outside the specified positions. Importantly, the fact that Keytruda SC itself contains no phenolic preservative did not avoid infringement in light of the fact that the Court had decided the claim should be interpreted as a product claim with functional characteristics.

The decision is also notable for its cross-border aspects. The Court held that there was sufficient evidence of threatened infringement in the Netherlands and the other countries for which relief was sought. It declined to stay the foreign infringement claims pending national validity proceedings. Applying BSH v Electrolux (in place of the Dutch Supreme Court decision in Roche/Primus II), it considered there was no reasonable and non-negligible likelihood of the relevant foreign parts being held invalid, noting both its own validity findings and the treatment of EP 622 in parallel German proceedings (where EP 622 has received a positive preliminary opinion from the Bundespatentgericht). The resulting injunction extends to Belgium, Denmark, France, Ireland, Italy, the Netherlands, Sweden and Switzerland. For the foreign designations, however, the injunction ceases to have effect if the relevant national part is subsequently found invalid and can revive if that finding is overturned on appeal.

The Court went further in relation to MSD’s central European marketing authorisation. Although merely holding a marketing authorisation is not itself a reserved act under Dutch patent law, intentionally facilitating or inducing infringement may constitute a tort. The Court therefore restrained MSD from facilitating infringement by its group companies in Belgium, Denmark, France, Ireland and Italy, including by permitting use of, or making available, its central marketing authorisation for Keytruda SC.
 

UK

The Government publishes response to the Intellectual Property Office's consultation to Standard Essential Patents.

The UK Government has published its response to its Consultation on Standard Essential Patents (SEPs), setting out a package of measures intended to make SEP licensing and FRAND dispute resolution more transparent, predictable and accessible.

Notably, the Government has decided not to proceed with a previously proposed Rate Determination Track (RDT) in the Intellectual Property Enterprise Court, concluding that the evidence did not demonstrate that a dedicated track would provide a sufficiently workable solution.

Instead, it will discuss with the judiciary a court-anchored Early Neutral Evaluation (ENE) style FRAND determination mechanism in ongoing SEP/FRAND UK proceedings. The proposal could provide for an automatic stay in “appropriate FRAND cases” to allow the parties to undertake ENE or another form of alternative dispute resolution. ENE was said to be particularly well suited to the Court’s handling of FRAND disputes since it retains judicial oversight. Details as to how the proposal would operate in practice, such as what an “appropriate FRAND case” might be or when ENE would take place, are yet to be determined.

The Government also intends to publish non-binding FRAND licensing guidelines explaining how parties should engage with the new package of measures, as well as separate guidance addressing negotiation conduct and what may be considered “bad faith” behaviour during negotiations. Finally, the UK’s IPO will consult on a voluntary, non-binding IPO-led FRAND opinion service, intended to provide an early indication of whether a proposed licence offer falls within a plausible FRAND range.
 

UPC

Court of Appeal provides guidance on electronic signatures and language of proceedings in Esko dispute.
[Esko v In(k)Control UPC-CoA-73/2026]

The Court of Appeal (CoA) has confirmed the limited circumstances in which it will interfere with First Instance determinations concerning language and has also provided clarity on formalities relating to electronic signatures on filed pleadings. The appeal arose from an attempt by the defendants, Esko Software and Esko Graphics, to overturn a decision of the Brussels Local Division (LD), refusing to change the language of proceedings from Dutch to English under Art. 49(5) UPCA.

The Court first addressed an argument raised by the claimant regarding the validity of the appeal. The claimant, In(k)Control, contended that the appeal documents had not been signed using an electronic signature within the meaning of the eIDAS Regulation and were therefore defective. Rejecting that submission, the Court held that r. 4.1 RoP requires only that documents be signed and lodged electronically. Neither the RoP, the UPCA nor case law imposes any requirement that the signature must be a qualified or advanced electronic signature. Case law establishes only that pleadings themselves must be signed by an authorised representatives and that secure authentication through the CMS alone is insufficient. A scanned handwritten signature applied electronically by authorised UPC representatives was therefore sufficient.

On the question of language, which had been decided by the Brussels LD to be Dutch but with the defendants arguing for English, the Court reiterated that the Court of First Instance has a broad discretion when determining requests under Art. 49(5) UPCA and that appellate review is limited to examining whether that discretion has been misused, not exercised, or exceeded. Applying that standard, the Court found no error in the Brussels LD’s reasoning.

The Brussels LD was entitled to place significant weight on the fact that all parties were established in the Dutch-speaking region of Belgium. Although the defendants argued that English was the natural language of the dispute because the patent had been granted in English, correspondence between the parties had been conducted in English and English was commonly used in the relevant technical field, the Court considered that these factors did not outweigh the parties’ location. The Court also rejected the suggestion that the defendants’ connection to a larger international corporate group justified a different conclusion. The relative size of the parties was a further consideration. Referring to case law and the UPC’s objective of facilitating patent enforcement by smaller businesses, the Court opined that the burden of English-language proceedings should not be imposed on the smaller claimant.
 

New episodes: You, Me and the UPC: Case by case

Episode 97: Brussels Local Division rejects disclosure requests and confirms entitlement may be raised as a defence

Episode 98: Court of Appeal (CoA) grants NVIDIA reinstatement following earlier CoA clarification on conditional revocation appeals