When can a product infringe a patent even if it falls outside the wording of the claims?
A recent judgment from the Swedish Patent and Market Court of Appeal (PMCA) provides important guidance on the doctrine of equivalents in Swedish patent law.
The case concerned Takeda’s patent covering certain L-lysine-d-amphetamine compounds used in ADHD medication. A generic company planned to launch a product containing L-lysine-d-amphetamine diadipate – a compound not explicitly covered by the patent claims. Even so, the PMCA held that the product would infringe the patent by equivalence.
The judgment clarifies several important issues.
First, the PMCA confirms that amendments to patent claims made to satisfy the requirement of support in the original application do not prevent a finding of infringement by equivalence. This distinguishes such amendments from limitations introduced to overcome prior art objections relating to novelty or inventive step.
Second, the court provides guidance on the burden of proof in patent infringement cases. Even though equivalence is ultimately a legal assessment for the court, the patent holder must invoke and prove the factual circumstances supporting an equivalence finding.
Finally, although Takeda was ultimately successful with its infringement by equivalence defence, successful equivalence claims remain relatively rare in Sweden. Over the past decade, such claims appear to have succeeded in only a handful of cases, often involving pharmaceutical patents and generic products.
The judgment also raises interesting strategic questions. Instead of launching its product “at risk” or challenging the patent’s validity, the generic company chose to bring a negative declaratory action – a relatively uncommon approach in Sweden, particularly shortly before the patent’s expiry.
A more detailed analysis of the judgment is available in the article written by Anna Bladh Redzic and David Ramsjö.