Good afternoon and happy Friday from ClaimWise!

A recent analysis by Daniel Borgogni explores how the Unified Patent Court may approach the Doctrine of Equivalents (DoE) and what this means for patent enforcement in Europe. The DoE extends patent protection beyond the literal wording of claims, ensuring that minor modifications do not allow competitors to circumvent patents. However, different European jurisdictions have long applied varying standards, leading to legal uncertainty for litigants.

With the UPC now adjudicating cross-border patent disputes, it faces a crucial decision: will it unify these interpretations or allow national traditions to persist? A clear and consistent standard could bring greater predictability, while a fragmented approach may encourage forum shopping and inconsistent outcomes. The court’s early rulings provide some direction, but key questions remain unanswered.

Diverging national approaches

Borgogni outlines how the leading European patent jurisdictions have developed distinct interpretations of the DoE. In Germany, courts apply a three-step test, assessing whether the accused product achieves the same technical effect, whether a skilled person would recognize that it operates similarly, and whether the alleged modification remains within the scope of the patent’s claims. Additionally, German law recognizes the Formstein defense, which prevents patentees from extending protection to equivalents that would have been obvious from prior art.

In the United Kingdom, courts historically relied on purposive construction rather than a distinct DoE. This changed with the 2017 Actavis v. Eli Lilly decision, which introduced a structured framework for assessing equivalence. Unlike Germany, the UK allows for prosecution history estoppel, meaning that a patentee cannot later claim equivalence for subject matter they explicitly gave up during prosecution.

France takes one of the broadest approaches to equivalence, focusing on whether a variant performs the same function and achieves the same result, without requiring it to operate in the same way. This functional interpretation makes France a favorable jurisdiction for patentees but raises concerns about legal certainty for third parties.

The Netherlands, as Borgogni explains, follows a structured balancing approach, weighing technical equivalence, fair protection for patentees, and legal certainty for third parties. Dutch courts also exhibit flexibility regarding the reference date for equivalence, sometimes favoring the infringement date over the priority date, allowing later technological developments to be considered.

By contrast, Italy lacks a consistent approach. Courts may apply the function-way-result test, akin to the U.S. standard, or instead focus on whether the variant demonstrates an original technical contribution. This variability makes Italian equivalence rulings less predictable.

The UPC’s emerging approach and open questions

Turning to the UPC’s early decisions, Borgogni highlights its first substantive ruling on equivalence, issued by The Hague Local Division in Plant-e Knowledge v. Arkyne (link to an excellent explanation of the case by Matthew Naylor. In that case, the court followed Dutch precedent, applying a structured analysis that incorporated both technical equivalence and fairness considerations. However, several key issues remain unresolved.

One major question is whether the UPC will develop a single, harmonized test or whether local divisions will continue to reflect their national traditions. Early rulings suggest that some divisions may retain regional influences, which could undermine the goal of consistency and encourage forum shopping—where litigants strategically select venues based on favorable interpretations of equivalence.

Another unresolved issue is the role of prosecution history estoppel. Some early UPC rulings have considered a patent’s prosecution history, while others have ignored it entirely. German and Italian courts reject prosecution history as a limiting factor, whereas France and the Netherlands often rely on it. The UK takes an intermediate position, restricting its use to cases where a patentee’s intent to exclude certain subject matter is explicit and unambiguous. The UPC’s Court of Appeal in Luxembourg will likely need to clarify whether file history will influence future equivalence assessments.

The reference date for determining equivalence is also contested. German and UK courts assess equivalence based on the priority date, ensuring that an invention’s scope is judged by what was known at the time of filing. Conversely, France and the Netherlands consider the infringement date, allowing for the possibility that new technological developments might be covered under equivalence. The UPC’s ruling in Plant-e followed the French model, but a definitive UPC-wide position has yet to emerge.

The status of the Formstein defense at the UPC is another point of uncertainty. This defense, long established in Germany, prevents patents from being extended to cover equivalents that would have been obvious in light of prior art. While the UK and the Netherlands have acknowledged similar principles, its application at the UPC remains unclear. If the court adopts Formstein, it would serve as a check against overly broad equivalence claims and help ensure that patents do not stifle legitimate innovation.

Conclusion

Borgogni’s analysis makes clear that the UPC’s handling of the Doctrine of Equivalents will have a profound impact on European patent litigation. While the court has an opportunity to establish a harmonized and predictable framework, its early decisions suggest that national influences may still shape outcomes.

For patent litigators and rights holders, the evolving approach to equivalence will influence litigation strategies, claim drafting, and enforcement decisions. If the UPC develops a clear, consistent test, European patent protection will become more predictable and stable. However, if local divisions continue to apply their own interpretations, legal uncertainty will persist, and forum shopping will remain a key consideration.

The UPC Court of Appeal in Luxembourg is expected to provide further guidance in the coming years. Whether its decisions will bring true harmonization or continued divergence remains to be seen. One thing, however, is certain: the debate over patent scope in Europe is far from settled.

Enjoy your weekend!