JUVE Patent

Arnold & Siedsma – Netherlands 2021

JUVE Comment

In this mixed IP firm, patent attorneys make up the majority of fee earners. And although patent prosecution across a broad technical spectrum accounts for the main portion of the firm’s work, some patent attorneys, such as Martin Luten for electronics 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.

The firm demonstrated its experience in electronics patent litigation on the side of Nikon in an extensive battle with ASML regarding semiconductors. With this battle settled in 2020, Ferring is now the highest profile litigation case the patent attorneys are involved in. They work hand in hand with lawyers from De Brauw and Bird & Bird in the Dutch patent cases here. The patent attorneys are also leading an attack on Serenity Pharma’s patent over desmopressin at the EPO.

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. However, the lawyers are not as visible as their counterparts at major Dutch litigation firms like Brinkhof. The team of four lawyers specialises more on soft IP.

The renowned prosecution practice is also registered for its technical specialties in AI patents and mechanics and mechanical engineering patents in the aviation sector. One of its main prosecution clients is Boeing, for whom it is heavily involved in EPO proceedings. Arnold & Siedsma also files and enforces numerous EPO patents for Samsung Electronics, another important client.


Litigation conducted by patent attorneys regarding pharmaceutical, electronic and mobile communication patents.

European strategy

With a subsidiary in Belgium, a presence in Switzerland and an office close to the EPO and the Boards of Appeal in Munich, the firm is present in important European venues for patent prosecution. If the UPC starts, Arnold & Siedsma would be in a good position to serve clients in important UPC locations.

2021 saw the firm widen its Belgian presence by fully merging with LC Patents. It now has offices in Brussels, Antwerp and Hasselt. This makes Arnold & Siedsma one of the most visible Benelux patent firms in Belgium.

Recommended individuals

Martin Luten (“excellent litigation support where general mechanical engineering matters are at stake”, competitor; electronics, mechanics, process and mechanical engineering); Hans Prins (“excellent patent attorney in EPO proceedings”, competitor; pharma and biotechnology)


21 patent attorneys, 1 lawyer


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: Ferring (claimant) in EPO opposition against Serenity Pharma’s patent over blood pressure lowering drug desmopressin; US company (claimant) against generic drug company over eyecare drug; Barco (claimant) against Delta Electronics regarding multimedia solutions; Profloating (defendant) against Ciel & Terre over photovoltaic panels;

Dutch company (defendant) against competitor in nullity suit against patent over groundwater recharging systems. Prosecution: patent filing: Adient Aerospace, Autonomous Medical Devices, Boeing, Corning Inc., Drylock, Illumina, Littlefuse, Samsung Electronics, Skylux (all public knowledge).


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