Lenz & Staehelin represents Samsung Bioepis in landmark patent nullity proceedings before the Federal Patent Court
On 12 August 2025, the Swiss Federal Patent Court issued its decision in case O2024_002, upholding the nullity action brought by Samsung Bioepis CH GmbH – part of the Samsung Bioepis group, the developer of the biosimilar Pyzchiva® – against Janssen Biotech, Inc., a Johnson & Johnson subsidiary.
The case forms part of a broader global dispute, with Janssen defending its blockbuster Stelara® in several jurisdictions, including the UK, the Netherlands, Norway, and Denmark. At issue was European Patent EP 3 883 606, which claims the antibody ustekinumab for treating ulcerative colitis. Ustekinumab is the active ingredient of Stelara®, one of Johnson & Johnson’s top-selling drugs worldwide, also approved for psoriasis, psoriatic arthritis, and Crohn’s disease.
The Court’s judgment is noteworthy not only for its outcome but also for the wide range of issues addressed – spanning both procedural and substantive patent law, notably legal interest, standard of proof, and prior use.
Legal interest
The Court reaffirmed that there is a public interest in removing wrongly granted patents, setting a comparatively low threshold for standing. It confirmed that a subsidiary has legal interest where a contested patent affects its business sphere – even if it is non-operational and merely holds a Swiss market authorization. In this case, Samsung Bioepis CH’s economic dependence on its parent company provided an additional basis, as the parent’s licensing revenues in Switzerland would have been reduced if the biosimilar could not be marketed.
Standard of proof
A central dispute concerned the Ochsenkühn poster. Samsung Bioepis argued that the poster had been presented at a June 2018 conference, while Janssen contested that Samsung Bioepis had failed to prove the version presented was the same relied upon in the proceedings. The Court ultimately accepted Samsung Bioepis’s position, relying heavily on the testimony of Prof. Ochsenkühn, who was examined during the main hearing – a rare occurrence in Swiss patent litigation. His testimony was deemed consistent and credible.
Prior use
The most consequential part of the ruling was the Court’s finding of prior use. In his testimony, Prof. Ochsenkühn also confirmed that participants in the underlying clinical trial:
- knowingly received ustekinumab (Stelara®) off-label for ulcerative colitis,
- followed the Crohn’s disease dosing regimen,
- were aware of risks associated with concomitant corticosteroids, and
- were under no duty of confidentiality, being free to share their experiences.
On this basis, the Court found his testimony reliable and confirmed prior use – a finding exceptionally rare in Swiss patent practice.
Conclusion
The Federal Patent Court held that the Swiss and Liechtenstein parts of EP 606 – as granted and in all admissible auxiliary requests – were either not novel or not inventive over the Ochsenkühn study.
This successful result was made possible by the strong teamwork of partner Thierry Calame and counsel Barbara Abegg (both IP), together with Christoph Fraefel of SBMP, Scott Parker and Fergus Brown from Simmons & Simmons and Sebastien Versaevel.