Deals & Cases

Patent owner Bayer HealthCare LLC filed a request for preliminary injunction based on the Swiss/Lichtenstein part of its European Patent EP 2 305 255 B1 (EP 255) against generic company Helvepharm AG (belongs to the Zentiva group of companies) and its generic product “Sorafenib Zentiva” with the Swiss Federal Patent Court in October 2021. EP 255 protects the active ingredient sorafenib in the form of its tosylate salt. Sorafenib is a multikinase inhibitor for the treatment of primary kidney cancer, advanced primary liver cancer and advanced thyroid carcinoma and is marketed by Bayer under the brand name Nexavar®. Nexavar® received the orphan drug status in the EU and the US.

In the preliminary injunction proceedings Helvepharm did not dispute the infringement of EP 255 by its product “Sorafenib Zentiva” but raised the objection of invalidity, mainly based on an alleged lack of inventive step of Bayer’s patent. It was undisputed amongst the parties that the active ingredient Sorafenib was already known in the prior art, but that the solubility of the free base of this substance was known to be poor, indicating a low bioavailability. In summary, Helvepharm argued, that the skilled person would have conducted routine tests with sorafenib tosylate and would have found that the dissolution rate of sorafenib tosylate, despite its low solubility, is sufficiently high that it can be seriously considered as a candidate for formulating an oral dosage form with a prospect of success. Bayer on the other hand argued that the skilled person would not have even included the tosylate salt of sorafenib in a salt-screening in the first place, that the skilled person would not have determined the dissolution rate of sorafenib tosylate due to its low intrinsic solubility and that the dissolution rate of sorafenib tosylate could not be experimentally determined at the priority date by routine testing in any case.

While Bayer’s patent was already determined invalid by courts in Germany, France, UK, Spain and the Netherlands for lack of inventive step, the Swiss Federal Patent Court (in line with the Commercial Court of Vienna) confirmed the validity of EP 255. The court concluded that Helvepharm has not shown that the dissolution rate of sorafenib tosylate could be determined with the usual methods in the prior art at the priority date and what the result of such determination would have been. The ordinary proceedings on the merits in this case are pending before the Swiss Federal Patent Court.

Bayer HealthCare LLC was represented by MLL Legal’s Simon Holzer (Partner, Head of the Patent and Life Sciences team), Ulrike Ciesla (Partner, European Patent Attorney) and Louisa Galbraith (Senior Associate).