On 15 September 2021, the Barcelona Court of Appeal confirmed the dismissal of a preliminary injunction (PI) request filed by Sanofi against Mylan for alleged patent infringement, in relation to an insulin glargine biosimilar product. With this decision, the Court updated and reinforced its current doctrine regarding the requirement of urgency in PI patent cases.


In general, two requirements must be fulfilled in order to grant a PI in a patent infringement case:

  • prima facie validity and infringement of the patent; and
  • danger in the delay (ie, justification of an urgency, so as to prevent irreparable harm being caused while the main proceedings on the merits are pending).

In some decisions the Court has considered that "urgency" would derive directly from the risk of the start or continuation of the patent infringement – that is, from the risk of launch onto the market or continuation in the commercialisation of the allegedly infringing product during the life of the patent. However, in other decisions, especially in recent years, the Court has recognised that the above would not be enough as such, and that a real and specific risk must be justified in every particular case.


Sanofi is the owner of European Patent 2 346 552, which does not claim a pharmaceutical invention, but an injectable drug delivery device, such as a syringe or a pen, with certain technical features. Although Sanofi commercialises two insulin glargine injectable pens, they do not constitute embodiments of the patent. A third party, Lilly, has been selling an injectable insulin glargine biosimilar since 2015.

In September 2020, Mylan started commercialising its insulin glargine biosimilar in the form of a pre-filled injectable pen (Semglee). Sanofi, which had sued Mylan for infringement of the patent, requested a PI asking the court to prohibit the commercialisation of Semglee, as it considered that its injectable pen would comprise all of the features of the device claimed in the patent. Regarding urgency, Sanofi alleged that it would be inherent to the patent infringement as such. Also, Sanofi added that since in the proceedings on the merits it could claim only a royalty for the sales that Mylan could make on its product (due to the lack of exploitation of the patent), such sales would cause irreparable harm to its business.

In turn, Mylan referred to the doctrine of the Barcelona Court of Appeal, according to which a real and specific risk must be justified in every particular case, and alleged that this was not so for many reasons. In this regard, Mylan emphasised that insulin glargine belongs to the public domain, and that Sanofi could not link the sales of its medicinal products to the patent, as its injectable pens were not an embodiment of the invention. Mylan also highlighted that the lack of exploitation of the patent on Sanofi's part would eliminate urgency in this specific case. As well as all of the above, it also argued that, in any event, its product had the same price as Sanofi's and Lilly's, and that sales data did not predict a significant drop in Sanofi's sales due to the commercialisation of a further insulin glargine biosimilar.


At first instance the Commercial Court No. 1 of Barcelona dismissed Sanofi's PI request, though it did so on other grounds and did not look into the issues regarding danger in the delay. Sanofi appealed the decision.

The Barcelona Court of Appeal dismissed Sanofi's appeal, thus confirming the rejection of the PI request. On this occasion, the Court specifically addressed the dispute between the parties regarding urgency.

In its decision of 15 September 2021, the Court referred to previous decisions and explained that, although the approach to urgency used to be debated within the Court due its case-by-case nature, the prevailing criterion for some time now has been that, as such, the commercialisation of the infringing product is not enough. Rather, a specific risk must be justified in every particular case.

Applying this approach to the case at stake, the Court concluded that there was no urgency. In this regard, it argued that Sanofi could not allege a possible loss of market share of its medicinal products since it did not hold a monopoly over insulin glargine: the asserted patent did not relate to the drug, but to an administration device. Also, the Court stated that the fact that Sanofi could claim only a royalty for Mylan's sales due to the lack of exploitation of the patent on its part constituted a legal limitation that could not be alleged as harm or damage.

This decision is final.

For further information on this topic please contact Núria Ribera‚Äč at Grau & Angulo by telephone (+34 93 202 34 56) or email ([email protected]). The Grau & Angulo website can be accessed at