On 28 July 2026, the Court of Appeal of The Hague handed down its long-awaited judgment in the appeal proceedings between Sandoz and Bayer concerning Bayer’s dosage patent for the anticoagulant rivaroxaban (Xarelto). Overturning the District Court’s 2023 judgment, the Court of Appeal revoked the patent for lack of inventive step and dismissed Bayer’s infringement claims.
Bayer is the proprietor of EP 1 845 961 B1 (“EP 961”), which claims the use of a rapid-release tablet of rivaroxaban for the manufacture of a medicament for the treatment of thromboembolic disorders, administered no more than once daily for at least five consecutive days. At first instance, the District Court of The Hague had held that EP 961 was valid and infringed and granted Bayer an infringement injunction against Sandoz. The Court found that, taking the Harder poster as the closest prior art and read together with the known short half-life data from the Kubitza studies (4–6 hours, as opposed to the 9–12 hours suggested, but not pharmacokinetically substantiated, in the Harder poster), the skilled person would not have had a reasonable expectation of success for a once-daily dosing regimen in patients. Therefore, the patent was found to contain an inventive step. Sandoz appealed against this decision.
Decision of the Court of Appeal
On appeal, Sandoz relied on a new prior-art document which had been obtained via a request under the Open Government Act: a Dutch-language patient information form and booklet that had been provided to participants in Bayer’s Phase II Einstein-DVT clinical study before the priority date. The Court of Appeal first had to determine whether this document formed part of the prior art. Bayer argued that patients were bound by an implied duty of confidentiality given their special relationship with the investigators and the sponsor. The Court of Appeal rejected this argument, holding, with reference to the EPO Guidelines for Examination, that the mere theoretical possibility for a member of the public to access information suffices for public availability, absent an express or tacit confidentiality agreement. As two Dutch patients had received the document without any such confidentiality obligation, the Court reasoned that it formed part of the prior art.
The Court of Appeal then assessed whether the patient information disclosed the features of claim 1. It found that the statement that the medicine “is taken once daily and works quickly” disclosed both the once-daily regimen and, since a medicine can only work after release from the tablet, the rapid-release feature. The skilled person would identify the compound BAY 59-7939 as rivaroxaban through a routine internet search. As to efficacy and safety, the Court of Appeal reasoned that the skilled person would assume the Einstein researchers had a sound scientific basis for testing a once-daily dosage in Phase II, despite the known short half-life of rivaroxaban suggesting a twice- or three-times-daily regimen. The Court of Appeal held that the patient information disclosed the claimed subject-matter to such an extent that the skilled person would have arrived at the invention without inventive effort; in any event, the skilled person would have had a reasonable expectation of success in doing so. The same reasoning applied to dependent claim 2.
The Court of Appeal accordingly revoked the Dutch part of EP 961, dismissed Bayer’s infringement counterclaims, and ordered Bayer to pay the costs of both instances.
This ruling aligns the Dutch position with prior court decisions to invalidate EP 961 in France, Germany, the UK and South Africa, whereas the EPO’s Technical Board of Appeal and the Swedish court had previously upheld the patent.
It is currently unknown whether Bayer will lodge an appeal at the Supreme Court.
For further enquiries, please contact Jaap Bremer or Freek van den Oetelaar.
