The dispute concerns Bayer’s divisional patent EP 2 305 255, which expired in December 2022. This patent covers the tosylate salt of the active ingredient sorafenib, corresponding to Bayer’s cancer treatment drug Nexavar.

Bayer has initiated several legal actions to prevent the exploitation of generic versions of its drug in the European market.

In France, Bayer first sought a preliminary injunction against Teva in 2021. However, both the Paris Court of First Instance and the Court of Appeal rejected the request, finding that the patent’s validity was seriously challenged due to a lack of inventive step.

Subsequently, Bayer brought infringement actions on the merits against Biogaran, as well as against Viatris/Mylan, Zentiva, and Sandoz.

During the course of the French proceedings, Bayer also decided to amend the claims of its patent. In this highly complex matter, Biogaran challenged the validity of the amended patent on several grounds, including lack of novelty, lack of inventive step, added subject matter, and insufficient disclosure.

A joint oral hearing before the Paris Court of first instance for all ongoing proceedings against the generic companies was held in March 2025.
According to the decision rendered on July 2025, the Paris Court of first instance followed Biogaran’s arguments and declared void claim 12 of patent EP 255 as limited, considering that the subject-matter of this claim extends beyond the content of the application as filed and rejected all the claimants’ requests.