JUVE Patent

Arnold & Siedsma – Netherlands 2022

JUVE Comment

In this mixed IP firm, patent attorneys make up the majority of fee earners. Some patent attorneys, such as Martin Luten for electronics and mechanical patents, and Hans Prins in the pharma and biotechnology field, enjoy an excellent reputation for providing technical support in infringement and revocation proceedings before the Dutch patent courts.

The firm is also very visible in EPO proceedings, for example for Ferring. The patent attorneys are involved in one of the highest-profile litigation cases for this client. They work hand-in-hand with lawyers from De Brauw and Bird & Bird in the Dutch patent cases. The patent attorneys are also leading an attack on Serenity Pharma’s desmopressin patent at the EPO. Kawasaki is another important international client, which the firm advises extensively on robotics and heavy machinery, including in EPO oppositions against competitors.

Arnold & Siedsma also appears frequently with its own lawyers in small to midsized patent cases. For example, the firm represents a Dutch company over groundwater recharging systems and packaging for medicines. Arnold & Siedsma mainly conducts such proceedings with its own litigators, and it recently bolstered its lawyer ranks with a second partner from an Amsterdam firm. However, with the exception of some small to midsized patent cases, the lawyers are predominantly active in soft IP. In cases with greater commercial significance, the firm’s patent attorneys are mostly seen alongside specialists from law firms such as Bird & Bird, Pinsent Masons or De Brauw.

The renowned prosecution practice is also noted for its technical specialties in AI, electronics, mechanics and mechanical engineering. The aviation sector is also significant. Boeing is a key prosecution client here, for which the patent attorneys are heavily involved in EPO proceedings. Arnold & Siedsma also files and enforces numerous EPO patents for another important client, Samsung Electronics.


Litigation conducted by patent attorneys regarding pharmaceutical, electronics and mechanics patents.

European set-up

With the exception of larger EPO oppositions, Arnold & Siedsma is only occasionally active in pan-European battles. Work such as that for core client Nikon two years ago concerning a dispute with ASML over computer lithography machines is mainly thanks to the outstanding reputation of individual partners such as Martin Luten.

However, with a subsidiary in Belgium, including offices in Brussels, Antwerp and Hasselt, and seven offices in the Netherlands, Arnold & Siedsma is one of the most visible Benelux patent firms. In addition, Arnold & Siedsma has a presence in Switzerland and an office close to the EPO and Boards of Appeal in Munich, meaning the mixed firm is present in important European venues for patent prosecution. When it comes to the UPC, Arnold & Siedsma is also in a good position to serve clients in important UPC locations, especially with its successful mixed approach. Nevertheless, the firm will not rely exclusively on its own litigators in UPC cases, but will instead continue to work on a case-by-case basis with those law firms with which it currently cooperates in national cases.

Recommended individuals

Martin Luten (“stands out from other litigators we have seen on the opposing side”, competitor; electronics, mechanics, process and mechanical engineering), Hans Prins (pharma and biotechnology)


28 patent attorneys, 2 lawyers

Partner moves

Remco van Leeuwen (from Leeway)


Full service in IP with a strong focus on patents. Patent prosecution in a broad field of technologies, also EPO disputes and revocation cases. Infringement disputes mainly with external lawyers. Trademark disputes with the firm’s own lawyers.


Litigation: Barco (claimant) against Delta Electronics regarding multimedia solutions; Dutch company (defendant) against competitor in nullity suit over patent for groundwater recharging systems; Dutch company against competitor over packaging for medicines; Kawasaki (defendant) against Thyssenkrupp and IKN in EPO oppositions over cooling systems for construction machines; Ferring (opponent) in EPO opposition against Serenity Pharma’s patent for blood-pressure-lowering drug desmopressin. Prosecution: filing for Ampleon, Boeing, Corning, Drylock, llumina, Kawasaki, Littelfuse, Nikon, Rijk Zwaan, Samsung Electronics, Schreder (all public knowledge).


Amsterdam, The Hague, Breda, Enschede, Eindhoven, Leeuwarden, Nijmegen