May a seizure regarding counterfeiting continue after patent expiration?

The duration of protection of a patent is finite. Once this date has passed, the market is basically free. But what happens to products seized just before this expiration date for alleged infringement? Should these goods be released as soon as the patent expires, or may the patentee maintain the seizure as security for damages?

In a ruling dated September 11, 2025, the Brussels Court of Appeal clarifies. The Court ruled that a protective seizure of products must be lifted after expiration, partly in the interest of public health. By contrast, the seizure of evidence (documents) may be maintained indefinitely in time, in order to safeguard the evidence on the merits.

The facts and procedural background

The case revolves around the pharmaceutical company Eisai, holder of a European patent and supplementary protection certificate (with pediatric extension) for the active ingredient ‘eribulin,’ used in the breast cancer drug Halaven. This protection right expired in Belgium on Dec. 16, 2024.

Leading up to this expiration date, Eisai suspected that the Cenexi company was committing infringing acts. Eisai obtained permission in November 2024, via a unilateral petition, to execute a seizure regarding counterfeiting . This included not only a description, but also an actual seizure (confiscation) of the stock of products and relevant documents at Cenexi.

Cenexi filed third-party opposition. At first instance, the president of the enterprise court ruled that the actual seizure of the products was only valid until the expiration date of the patent (Dec. 16, 2024), after which the products had to be released. Eisai appealed this and demanded that the seizure of the products be maintained beyond the expiration date.

Court of Appeal decision

The Brussels Court of Appeal largely upheld the first judge's decision, but introduced a crucial nuance between products and documents.

The Court ruled on the basis of Article 1369a/1 of the Judicial Code, which requires the court to balance interests.

1. Regarding the products (drugs): The Court stated that maintaining the seizure beyond December 16, 2024 was not necessary or reasonably justified. Since the exclusive right had expired, third parties were free to manufacture and export the product. The interests of public health (access to cancer treatment) and free competition outweighed Eisai's limited interest in holding the goods as collateral for possible damages.
2. Regarding the documents: Here, the Court ruled otherwise. After all, the seizure of documents does not serve to foreclose the market, but to secure evidence. The Court overturned the time limitation for the documents: they may remain seized even after the expiration of the patent so that Eisai can use them in proceedings on the merits to prove past infringements.

Legal analysis and interpretation

This ruling goes to the heart of the ratio legis behind counterfeit seizures. Seizure regarding counterfeiting is a powerful tool in Belgian law, designed to gather evidence and - in certain cases - put an end to a continuing infringement.

The balancing of interests as a corrective mechanism

Article 1369bis/1, §5 of the Judicial Code forces the court to test whether the measure is “reasonable and necessary,” taking into account the specific circumstances. The Court here confirms that an actual attachment of products (the physical removal of goods from the market) is primarily a measure to protect the exclusive right during its period of validity. Once the right expires, the rationale for this far-reaching market restriction expires. The mere fact that the patent holder is still claiming damages for past infringements does not justify competitors (and patients) remaining blocked after the expiration date.

Importantly, the Court emphasized that the patent holder is not left disenfranchised. Although the seizure of the products is lifted, the holder retains the right to claim measures on the merits as provided in Articles XI.334 and XI.335 of the Code of Economic Law (CEL). These include damages or the release of profits for infringements committed during the patent's term of validity. For these claims, preservation of the seized documents is essential.

Evidence gathering is independent of the duration of protection

The document decision is dogmatically pure. Patent infringement litigation on the merits can take years and is often not initiated or concluded until after the patent has expired. As the Court correctly states, all relevant evidence must remain untouched and accessible. It would be illogical if evidence of infringement had to be destroyed or returned simply because the patent is now no longer valid. After all, the infringement took place when the patent was still valid.

This approach is consistent with the European Enforcement Directive (2004/48/EC), which distinguishes between evidence protection measures and measures that prevent the circulation of goods.

What this specifically means for you

This case law affects both patent holders and generic manufacturers or competitors.

• For the patent holder: Be aware that an actual seizure of inventory is temporary in nature that is inextricably linked to the life of your IP right. You can rarely stop the release of goods after the expiration date. Your focus in a seizure shortly before the expiration date should be on securing documents and data. This is your ammunition for the later claim. Make sure your petition explicitly distinguishes this.
• For the alleged infringer (competitor): Are you facing a seizure just before the expiration date of a patent? Then it is essential to demand the release of your products as of the expiration date via third-party opposition or in summary proceedings. You can invoke the public interest (especially in the pharma sector) and freedom to conduct a business. The Court of Appeal confirms that you cannot remain hostage to an expired right.
• For health care (and public interest): The courts are increasingly taking into account external factors such as public health. Unnecessary restriction of drug supply after patent expiration will not be tolerated.

Frequently Asked Questions (FAQ)

What is the difference between a descriptive seizure and a protective seizure?
In a descriptive seizure, the court expert describes the allegedly infringing goods and processes to establish evidence, without taking the goods. In a protective seizure, the goods are physically seized and the merchant is not allowed to dispose of them.

Can I claim damages for infringements committed during the validity period, even if the patent has now expired?
Yes. The expiration of the patent only means that third parties may release the product from that moment on. For acts committed while the patent was still valid, the holder retains the right to claim damages through proceedings on the merits.

Why are documents allowed to remain seized after patent expiration?
Documents serve as evidence in the lawsuit to determine the extent of infringement and damages. This evidence must remain available while the lawsuit is pending, regardless of whether the patent has since expired.

Conclusion

The ruling of Sept. 11, 2025 creates clarity: the protection of an intellectual property right effectively ceases on its expiration date. The instruments of seizure regarding counterfeiting may not be abused in Belgium to artificially prolong a monopoly to the detriment of the free market and the public interest. However, the right of proof remains unimpaired.