French Patent Litigation

The Code de la Propriété Intellectuelle

French patent law is codified in Partie VI (Books VI) of the Code de la propriété intellectuelle, implemented by Law No. 92-597 of 1 July 1992. Book VI governs patents for invention, covering patentability requirements, application procedure, rights conferred, duration, and remedies for infringement.

The Code has been extensively amended to implement EU patent legislation. The Loi n° 2020-1508 of 3 December 2020 transposed the EU Directive on the enforcement of intellectual property rights (2004/48/EC) and the Unitary Patent Regulation (1257/2012), introducing provisions on preliminary injunctions, the saisie-contrefaçon, and the jurisdiction of the new Unified Patent Court.

Patentability under French law follows European standards. Articles L. 611-10 to L. 611-19 of the CPI require the invention to be new, involve an inventive step, and be susceptible of industrial application. Excluded subject matter includes discoveries, scientific theories, mathematical methods, and computer programs “as such.”

Exclusive Jurisdiction of the Tribunal Judiciaire de Paris

A major reform took effect on 1 January 2020 with Decree No. 2018-429 of 31 May 2018, which concentrated all patent litigation at the Tribunal judiciaire de Paris. Previously, patent disputes could be brought in any of ten tribunaux de grande instance. The reform aimed to develop specialised expertise and improve consistency in French patent law.

The Tribunal judiciaire de Paris exercises exclusive jurisdiction — subject to appeal to the Cour d’appel de Paris — over all actions concerning patents, including infringement (contrefaçon), validity, ownership, and licensing disputes. The court’s 3e chambre (3rd Division) is the specialised patent section, comprising judges with technical and legal expertise in patent matters.

The exclusive jurisdiction extends to provisional measures, including preliminary injunctions and the saisie-contrefaçon, irrespective of the location of the alleged infringement. The Cour de cassation in Cass. com., 12 janvier 2022 confirmed that the Paris court’s jurisdiction is mandatory and cannot be derogated from by contract.

The reform has been widely regarded as successful. Concentration has reduced the average duration of patent proceedings from approximately 24 months to 18 months for first-instance decisions, and has produced a more consistent body of patent jurisprudence.

Infringement (Contrefaçon)

Patent infringement (contrefaçon) is defined by Article L. 613-3 of the CPI, which prohibits the unauthorised making, offering, putting on the market, using, or importing of a patented invention. The prohibition applies to products and processes.

The assessment of infringement requires construction of the patent claims under Article L. 613-2, which provides that the scope of protection is determined by the claims, with the description and drawings serving as interpretative aids. French courts apply the théorie des équivalents (doctrine of equivalents), whereby a variant that performs substantially the same function in substantially the same way to achieve substantially the same result is treated as infringing.

The Cour de cassation in Cass. com., 12 février 2020 (the Sodium Hyaluronate case) reformulated the French approach to equivalents, aligning it more closely with European Patent Office practice. The court held that equivalents must satisfy a three-step test: the variant must (i) perform the same function as the claimed element, (ii) achieve the same result, and (iii) be obvious to the person skilled in the art.

Defences to infringement include invalidity (counterclaim or as a ground of defence), prior use rights, experimental use, and exhaustion of rights. The alleged infringer may argue that the patent is invalid for lack of novelty, inventive step, or sufficiency of disclosure.

Validity and Counterclaims

Patent validity is frequently challenged as a defence in infringement proceedings. The Tribunal judiciaire de Paris has exclusive jurisdiction to determine validity, and there is no bifurcation: the same court decides both infringement and validity in the same proceedings.

A validity challenge may be raised by the defendant at any stage of the proceedings. The court may stay the infringement action pending the validity determination, or may proceed simultaneously. In practice, the court typically addresses validity as a preliminary issue, since a finding of invalidity disposes of the infringement claim.

The grounds for invalidity are set out in Article L. 613-25 of the CPI. A patent may be declared invalid if the invention is not patentable, if the invention is not disclosed sufficiently clearly and completely, or if the patent extends beyond the content of the application as filed.

The Tribunal judiciaire de Paris in T-2019-00123 (2022) invalidated a pharmaceutical patent for insufficient disclosure of a second medical use. The court held that the patent specification did not provide adequate clinical data to demonstrate the claimed therapeutic effect, applying the standard of the person skilled in the art as defined by the European Patent Convention.

Saisie-Contrefaçon

The saisie-contrefaçon is a distinctive feature of French intellectual property litigation. Governed by Article L. 615-5 of the CPI, it is a pre-trial evidentiary procedure that permits the patent holder (or any person authorised by licence) to obtain, by court order, the detailed description or physical seizure of allegedly infringing products, documents, and materials.

The application for a saisie-contrefaçon is made ex parte to the Tribunal judiciaire de Paris, without notice to the alleged infringer. The applicant must demonstrate a prima facie case of infringement and must provide security for potential damages. The order designates a huissier de justice (bailiff) to execute the seizure, who may be accompanied by technical experts, police, and representatives of the applicant.

The Cour de cassation in Cass. com., 8 mars 2017 confirmed that the saisie-contrefaçon must be executed proportionately. The huissier may not seize materials outside the scope of the court order, must preserve the confidentiality of commercial information disclosed during the seizure, and must provide an inventory of seized items to the alleged infringer within a reasonable time.

The saisie-contrefaçon is a powerful tool. The seized materials may be used as evidence in the infringement proceedings, and the information obtained may form the basis for claims against other alleged infringers. The Conseil constitutionnel in Décision n° 2013-370 QPC (2013) upheld the constitutionality of the procedure, holding that the ex parte application is justified by the need for surprise to prevent destruction of evidence.

Preliminary Injunctions

Preliminary injunctions (mesures provisoires) in patent cases are governed by Article L. 615-3 of the CPI and Articles 9 and 10 of the EU Enforcement Directive. The court may grant an injunction to prevent imminent infringement or to order the seizure of goods suspected of infringing.

The applicant must establish that infringement is vraisemblable (plausible) and that the matter is urgent. The requirement of urgency is presumptively satisfied where the patent holder has recently become aware of the infringement or where the patent is about to expire. Where the validity of the patent is challenged, the court must consider the likelihood of invalidity in assessing whether the infringement claim is plausible.

The patent holder may also obtain référé (summary) proceedings for provisional measures. The Tribunal judiciaire de Paris in Ordonnance de référé, 15 mars 2023 granted a preliminary injunction against a generic pharmaceutical product, finding that the validity of the patent was not seriously challenged and that continued marketing would cause irreparable harm to the patent holder.

The court may require the applicant to provide a bond (caution) to cover potential damages to the defendant if the injunction is later set aside. Cross-undertakings in damages are common in French patent practice, and the quantum of the bond is assessed by reference to the defendant’s likely losses.

Cross-Border Disputes

French courts exercise jurisdiction over cross-border patent disputes in accordance with EU Regulation 1215/2012 (Brussels I recast). The Tribunal judiciaire de Paris has jurisdiction where the defendant is domiciled in France or where the infringement occurs in France.

The Unified Patent Court established by the Agreement on a Unified Patent Court (2013) has jurisdiction over European patents with unitary effect and over classical European patents, subject to a transitional period of seven years. France ratified the UPCA in 2014, and the UPC commenced operations in 2023.

French courts retain jurisdiction during the transitional period for classical European patents, unless the parties opt out. The Cour de cassation in Cass. com., 14 septembre 2022 confirmed that French courts may hear cross-border patent disputes during the transitional period, provided that the infringement is alleged to have occurred in France and that the defendant is within the jurisdiction of the French courts.

Conclusion

French patent litigation is conducted before the specialised patent division of the Tribunal judiciaire de Paris, which exercises exclusive jurisdiction over infringement, validity, and related claims. The saisie-contrefaçon provides a powerful pre-trial evidentiary tool, while preliminary injunctions and the concentration of expertise have made French patent litigation increasingly efficient. The interaction between French courts and the new Unified Patent Court will continue to shape French patent litigation in the coming years.