Attorney at Law & Partner
Attorney at Law & Partner
Attorney at Law
On 10 September 2025, the District Court of The Hague (“Court”) rendered its decision in the accelerated final relief proceedings between Samsung Bioepis UK Ltd. (“SB”) and Janssen Biotech Inc. (“Janssen”). The Court dismissed SB’s revocation action and upheld the NL part of EP 3 883 606 (“EP 606”) containing a second medical use of the active ingredient ustekinumab (marketed as Stelara).
This case follows earlier litigation in the Netherlands regarding the basic patent EP 1 309 692 (‘’EP 692”) and its SPC related to ustekinumab. In January 2024, the Provisions Judge of the District Court, denied Janssen a PI against SB. SB could benefit from the SPC Manufacturing Waiver for the production and stockpiling for export of its biosimilar products. This decision was confirmed by the Court of Appeal in February 2025 (see our Pharma Updates of 31 January 2024 and 19 February 2025). Both EP 692 and its SPC are now expired and the current dispute focuses only on EP 606.
Janssen markets ustekinumab under the brand name ‘Stelara’ for various immune-mediated inflammatory diseases, including psoriasis, psoriatic arthritis, Crohn’s disease, and, since 2019, ulcerative colitis (“UC”). Janssen obtained EP 606 as a second medical use patent for the treatment of UC.
SB started a revocation action claiming EP 606 is invalid due to lack of novelty, lack of inventive step and insufficiency of disclosure. Furthermore, SB argued that, with regard to claim feature 2.5, Janssen cannot claim priority on the basis of priority documents (P1, P2, P3). In the proceedings Janssen solely relies on priority documents P2 and P3.
Priority documents P2 and P3 – claim interpretation
The Court held that Janssen can rely on the priority document P2 because “week 0” in claim feature 2.5 must be understood as the start of the maintenance phase of the UNIFI study, and that CSFCR (corticosteroid-free clinical remission) must be achieved at week 44, and not merely before week 44, as SB contended.
The Court also clarified that based on the interpretation by the person skilled in the art, claim feature 2.5 does not require a specific level of statistical significance. It further notes that parties no longer disagree that claim feature 2.5 is not limited to patients who were on corticosteroids at the start of the study.
Novelty
SB further argued that EP 606 lacked novelty based on the UNIFI Protocol, the Ochsenkühn Abstract and Poster, and the Sands Abstract and Slides, or alternatively due to public prior use. The Court does not follow SB’s reasoning and rejects the arguments. None of the cited documents directly and unambiguously discloses claim feature 2.5; inherent disclosure is insufficient for novelty.
Inventive step
SB presented numerous inventive step attacks. It argued lack of inventive step based on the UNIFI Protocol (or in combination with the common general knowledge), the Ochsenkühn Abstract and Poster, and the Sands Abstract and Slides. The Court applied the PSA regarding inventive step. The Court emphasised that inventive step is only lacking if the skilled person in the art, starting from the prior art, would have had a reasonable expectation of success in solving the problem; a mere hope to succeed or the fact that a trial/study was “obvious to try” is insufficient. The threshold for a reasonable expectation of success depends on: i) the complexity and duration of the research and ii) the complexity of the technical problem to be solved.
The Court also addressed SB’s reliance on a recent TBA decision (T1941/21). From that decision follows that clinical trials are usually initiated on the basis of encouraging results from preclinical experiments. Thus, the announcement of a Phase II trial may provide a skilled person with a reasonable expectation of success. According to the Court this needs to be assessed on a case-by-case basis.
In assessing the specific circumstances of this case, the Court held that the prior art did not provide a reasonable expectation of success. In this case the threshold is high because of the: high endpoint of the UNIFI study, difficult patient population, and inconsistencies and limitations in the available data. Therefore, the Court held EP 606 inventive.
Sufficiency of disclosure
SB argued that EP 606 was not sufficiently disclosed. The Court held that these arguments were unfounded.
The Court notes that there are ongoing proceedings regarding the validity of EP 606 in the UK, Italy and Denmark. On 30 July 2024 the High Court of the UK, rendered its decision in final relief proceedings and found the UK part of EP 606 invalid for lack of inventive step based on the ‘Sands Abstract’ and the ‘Sands Slides’.
The Court further points out that in the US parties reached a settlement regarding the market entry of SB.
Based on its own assessment, the Court holds the NL part of EP 606 valid and dismisses SB’s revocation action.
Attorney at Law & Partner
Attorney at Law & Partner
Attorney at Law