Willem’s practice primarily consists of litigating in the field of intellectual property law. Willem acts before all the national courts (the courts of first instance, the courts of appeal and the Supreme Court). He also regularly litigates before the Court of Justice of the European Union (CJEU) and the European Patent Office (EPO). Willem is also involved in advising on European patent strategies and coordinating and conducting European patent proceedings. He is the adviser of many innovative Dutch and foreign multinationals, including pharmaceutical and biotechnological companies.
Willem is a professor of Intellectual Property Law at the University of Tilburg.
Willem is one of the founding members of HOYNG ROKH MONEGIER, he was the managing partner of HOYNG MONEGIER from 2011 until 2015, when the firm merged with German IP boutique ROKH IP and stepped down as a managing partner of HOYNG ROKH MONEGIER in January 2018.
Willem is a member of a select group of lawyers admitted to appear before the Dutch Supreme Court.
He is a member of the drafting committee of the Rules of Proceedings of the future Unified Patent Court (UPC) and member of the Advisory Committee of the UPC Preparatory Committee. He advises also the Dutch Ministry of Economic Affairs on UPC matters.