MSD v Halozyme (Rechtbank Den Haag, C/09/695432, 2026)

Dhenne Avocats · 23 October 2026

Our analysis

Summary

In a judgment of 7 October 2026 (C/09/695432 / HA ZA 25-1075), delivered under the accelerated regime for patent cases, the District Court of The Hague dismissed the claims of Merck Sharp & Dohme B.V. (MSD) for a declaration of non-infringement and for revocation of the Dutch part of Halozyme’s EP 2 797 622, and allowed Halozyme’s counterclaim: Keytruda SC, the subcutaneous formulation of pembrolizumab, falls within the scope of the patent in Belgium, Denmark, France, Ireland, Italy, the Netherlands, Sweden and Switzerland, and MSD is enjoined, subject to penalty payments, from marketing it in those countries (operative part, paras 5.1 to 5.11).

Facts and procedure

Halozyme owns EP 2 797 622, granted on 12 October 2016 without opposition and expiring on 27 December 2032, which protects variants of the PH20 polypeptide (a hyaluronidase) with increased stability in the presence of phenolic preservatives. MSD developed Keytruda SC, which combines pembrolizumab with berahyaluronidase alfa (ALT-B4) purchased from Alteogen, and holds the EU central marketing authorisation for the product, being also the manufacturer responsible for batch release. Group companies launched it in Denmark and Sweden while the proceedings were pending. MSD sued Halozyme on 1 October 2025 for a declaration of non-infringement and for revocation on grounds of insufficiency, added matter, lack of novelty and lack of inventive step. Halozyme counterclaimed for a declaration of infringement, a cross-border injunction and an order prohibiting MSD from facilitating infringement by other group companies. The oral hearing took place on 31 July 2026.

Question

Is the functional feature of increased stability in the presence of a phenolic preservative to be assessed on the polypeptide as such or in the formulation of the accused product, which contains no preservative, and may the Dutch court grant cross-border injunctions while revocation actions are pending in other states?

Decision

Claim 1 is a product claim with functional features: the proprietor may prohibit any act involving a modified polypeptide that has those features, whatever use the third party makes of it. Phenolic stability is therefore to be measured on the polypeptide as such, as in Example 5 of the patent, not in the Keytruda SC formulation (paras 4.49 to 4.53). All invalidity attacks fail (paras 4.54 to 4.84). The BionSystems tests filed by Halozyme show that ALT-B4 is more stable in the presence of m-cresol than unmodified PH20, whereas MSD’s tests, carried out on co-formulations with pembrolizumab, are not probative (paras 4.95 to 4.99). It is irrelevant that Keytruda SC contains no phenolic preservative and so does not exploit the technical effect of the invention, and legal certainty is not infringed (paras 4.100 and 4.101). As marketing authorisation holder and manufacturer responsible for batch release, MSD offers and puts Keytruda SC on the market in the countries concerned (para 4.107). The court declines to stay the proceedings under BSH v Electrolux, as there is no reasonable and non-negligible chance of revocation in the other states, having regard in particular to the preliminary opinion of the Bundespatentgericht and to the rejection of the invalidity arguments by the Munich Regional Court in interim proceedings (paras 4.109 and 4.110). The injunctions concerning the foreign parts of the patent lapse if the competent court revokes the relevant part. Penalty payments are set at EUR 25,000 per day or per product, capped at EUR 50 million, and MSD is ordered to pay EUR 284,760 in costs, all provisionally enforceable.

Key points for practice

• For a product claim with functional features, the feature is tested on the claimed product as such: choosing a formulation that does not exploit the technical effect does not avoid infringement (paras 4.50 and 4.101).
• Comparative tests must address the subject-matter of the claim: measurements on co-formulations, in which the active substance affects the result, cannot rebut tests carried out on the polypeptide alone (para 4.98).
• The marketing authorisation holder responsible for batch release may be enjoined from marketing in other states and from using its authorisation to facilitate infringement by group companies (paras 4.107 and 5.4).
• The court of the defendant’s domicile grants cross-border injunctions without awaiting foreign revocation actions where their prospects are neither reasonable nor non-negligible, subject to a condition subsequent of revocation by the competent court (paras 4.109, 4.110, 5.5 and 5.6).

Provisions applied

European Patent Convention

Articles 69, 83 and 123(2) EPC

Regulation (EU) No 1215/2012

Articles 4(1), 8(3) and 24(4)

Regulation (EC) No 864/2007

Article 8

Dutch Patents Act 1995

Article 80

Case law cited

CJEU, 25 February 2025, BSH Hausgeräte v Electrolux, C-339/22, ECLI:EU:C:2025:108, Hoge Raad, 6 March 2009, Schneider v Cordis, ECLI:NL:HR:2009:BG7411

Prepared by Dhenne Avocats from the official judgment (rechtspraak.nl), consulted on 23 October 2026. Only the official text is authoritative.