The District Court The Hague has upheld patent protection for prostate cancer drug Xtandi, dismissing nullity challenges from generic manufacturers Accord Healthcare and Sandoz. The ruling maintains exclusive protection for the active ingredient enzalutamide in the Netherlands until June 2028, effectively blocking generic competition.
Patent Protection Extended Through 2028
The court dismissed nullity suits against basic patent EP 1 893 196 and its Dutch supplementary protection certificate (SPC) 300632 in cases 23-903 and 23-904. The patent remains in force until March 29, 2026, with the SPC extending protection until June 25, 2028.
Patent owner The Regents of the University of California and exclusive sub-licensee Astellas successfully defended against challenges to the priority claims of EP 196. Generic companies argued that the lead compound, originally known as RD 162, had already been published at a conference before the patent filing, making the slightly altered version claimed in EP 196 B2 invalid due to lack of disclosure.
Generic Companies' Challenge Rejected
The court rejected the generic manufacturers' arguments regarding prior publication of the compound. Sandoz and Accord had disputed the patent's priority claims, contending that the previously published RD 162 compound undermined the novelty of the patented version. However, the Dutch court found these arguments insufficient to invalidate the patent.
The ruling follows a prolonged deliberation process. After oral hearings in June 2024, the court initially planned to deliver its decision in October 2024 but postponed the ruling several times before issuing the final judgment.
Broader European Patent Defense Success
This decision continues a pattern of successful patent defense across Europe for Xtandi-related intellectual property. The UK High Court and German Federal Patent Court previously upheld patents relating to enzalutamide. Earlier in 2024, the Dutch court also upheld formulation patent EP 3 725 778, demonstrating consistent judicial support for the patent portfolio.
The comprehensive patent protection strategy has effectively maintained market exclusivity for Xtandi across major European markets, preventing generic drug companies from launching competing enzalutamide products.
Pending Appeals and Future Litigation
While it remains unclear whether Accord and Sandoz will appeal this latest Dutch decision, both companies have demonstrated willingness to pursue appellate remedies. They previously filed an appeal against the Dutch court's decision on formulation patent EP 778 earlier this year.
In the UK, an appeal against the High Court's October 2024 ruling regarding EP 196 remains pending, indicating ongoing litigation across multiple jurisdictions. The parallel proceedings in the UK involve the same patent disputes, with Accord, Sandoz, and Teva challenging the patent validity.
Legal Representation and Industry Impact
The successful defense involved a mixed team from Hoyng ROKH Monegier representing Astellas and The Regents of the University of California, while Brinkhof acted for the challenging generic manufacturers. The case represents part of broader pharmaceutical patent litigation trends, where generic companies routinely challenge originator patents to enable earlier market entry.
The extended patent protection until 2028 maintains significant commercial value for the prostate cancer treatment, delaying potential cost savings from generic competition in the Dutch market.
