Hanging By a Thread – Samsung Invalidates Janssen’s UC Ustekinumab (Stelara®) Patent Application

Samsung Bioepis AU Pty Ltd v Janssen Biotech, Inc. [2025] APO 32 (3 October 2025)

Introduction

Samsung Bioepis (Samsung) has successfully opposed Janssen Biotech’s (Janssen) AU2019346134 patent application (AU134) for methods of treating ulcerative colitis (UC) with ustekinumab (Stelara®).  Samsung invalidated all of the AU134 claims on the grounds of lack of novelty and obviousness.  Samsung’s lack of support attack did not succeed.  This decision marks the end of the road for AU134, with Janssen choosing not to appeal the opposition decision to the Federal Court of Australia or to propose amendments aimed at overcoming the deficiencies in the claims.  The Australian Patent Office formally refused AU134 in January 2026, leaving one divisional application (AU2023201217) as the only surviving member of the AU134 patent family.

The IP Australia decision marks yet another success for Samsung in its Australian actions against Janssen regarding Janssen’s Australian ustekinumab patent portfolio for the treatment of UC.  On 9 June 2025, the Federal Court of Australia ordered the revocation of three Janssen Biotech innovation patents  (AU2024100006, AU2024100007 and AU2024100016).  In an earlier victory for Samsung Bioepis, Janssen surrendered two innovation patents (AU 2023100041 and 2023100042).

Background

The AU134 invention related to methods of providing a clinically proven safe and effective treatment of UC, particularly moderately to severely active UC in patients who had had an inadequate response to or were intolerant of a conventional or existing therapy, by intravenous and/or subcutaneous administration of an anti-IL-12/IL-23p40 antibody i.e. ustekinumab.

Claim 1 of AU134 claimed:

a)   A method of treating moderately to severely active UC in a subject in need thereof, comprising

b)   administering to the subject a pharmaceutical composition comprising an effective amount of an anti-IL-12/IL-23p40 antibody,

c)   wherein the antibody comprises a heavy chain variable region and a light chain variable region, the heavy chain variable region comprising: a complementarity determining region heavy chain 1 (CDRH1) amino acid sequence of SEQ ID NO:1; a CDRH2 amino acid sequence of SEQ ID NO:2; and a CDRH3 amino acid sequence of SEQ ID NO:3; and the light chain variable region comprising: a complementarity determining region light chain 1 (CDRL1) amino acid sequence of SEQ ID NO:4; a CDRL2 amino acid sequence of SEQ ID NO:5; and a CDRL3 amino acid sequence of SEQ ID NO:6,

d)   wherein after treating with the antibody, the subject is a responder to treatment by at least one measure of response to treatment

e)   selected from the group consisting of: (i) clinical remission based on at least one of the global definition of clinical remission with Mayo score ≤ 2 points with no individual subscore > 1 and the US definition of clinical remission with absolute stool number ≤ 3, rectal bleeding subscore of 0 and Mayo endoscopy subscore of 0 or 1, (ii) endoscopic healing with a Mayo endoscopy subscore of 0 or 1, (iii) clinical response based on the Mayo endoscopy subscore, (iv) mucosal healing, and (v) clinical response as determined by a decrease from baseline in the Mayo score by ≥30% and ≥3 points and a decrease from baseline in the rectal bleeding subscore ≥1 points or a rectal bleeding subscore of 0 or 1.

Key Issues

Novelty

Samsung alleged that four prior art publications anticipated the AU134 claims, with the Delegate giving the greatest consideration to the following prior art:

1. The record of the clinical trial titled “A Study to Evaluate the Safety and Efficacy of Ustekinumab Induction and Maintenance Therapy in Participants With Moderately to Severely Active Ulcerative Colitis (UNIFI)”and identifiable by ClinicalTrials.gov identifier NCT02407236 published on the ClinicalTrials.gov website on 13 August 2018 (CTR 236); and

2. Ochsenkühn, T., et al(2018) “P759 Ustekinumab as rescue treatment in therapy-refractory or -intolerant ulcerative colitis”, Journal of Crohn’s and Colitis, Volume 12, Issue supplement 1, published on 16 January 2018 (Abstract P759).

The Delegate held that all claims of AU134 were anticipated by one or both of CTR 236 and Abstract P579.

The Delegate held that CTR 236 anticipated each of claims 1-3, 6-19 and 22-30, but did not anticipate claims 4, 5, 20 or 21.  In reaching this conclusion, the Delegate had to grapple with the nature of the clinical trial disclosure in CTR 236.

Janssen argued that CTR 236 did not anticipate AU134 because it was a Phase III clinical trial protocol that did not contain any results, nor did it provide any rationale for why ustekinumab would treat moderately to severely active UC.  Rather, Janssen argued:

• it was a study designed to evaluate the safety and efficacy of ustekinumab in participants with moderately to severely active UC, and was the first clinical trial of ustekinumab in this patient population; and
• there was no teaching in CTR 236 of a ‘reasoned hypothesis’; it was no more than a disclosure of a ‘hypothesis to be tested’.

The Delegate disagreed, holding that Janssen’s position was inconsistent with previous Federal Court of Australia authority, in particular the decision of the Full Court of the Federal Court of Australia in Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd (Mylan).  In Mylan, the Full Court held that a clinical trial protocol which contained an hypothesis without scientific proof or substantiation could constitute an anticipatory disclosure (and did so in that case).  As it is not a requirement for patentability that an invention, as claimed, be based on scientific proof or substantiation, the Full Court in Mylan held that no greater requirement is imposed on a prior documentary disclosure in order for it to be anticipatory.

The Delegate considered that CTR 236 had disclosed the method of treatment, regardless of the proportion of participants in the CTR 236 Phase III clinical trials shown to demonstrate the defined primary and secondary outcome measures.  In addition, the Delegate considered that CTR 236 contained a clear direction, recommendation or suggestion to deliberately administer ustekinumab with an intended purpose of treating a subject with UC by achieving the defined primary and secondary outcome measures.

The Delegate then moved on to discuss Abstract P759.  Abstract P759 disclosed a small-scale study that aimed to “assess the clinical outcomes achieved with ustekinumab as rescue treatment in therapy-refractory or intolerant UC”.  The Delegate held that Abstract P579 anticipated claims 1-9, 17-28 and 30, but did not anticipate claims 10-16 or 29.

The Delegate considered that, even though ustekinumab was administered as an off-label treatment in Abstract P759 and to avoid surgery, it was apparent that ustekinumab was being used with the intended purpose to relieve or cure a patient with moderately to severely active UC.  The Delegate accepted that there might be limitations regarding the conclusions that could be drawn from retrospective studies, and that these studies were still important in the development of approaches to the treatment of inflammatory bowel disease.  However, even if there were limitations, these did not undermine the disclosure in Abstract P759.  As a result, the Delegate considered that the off-label use of ustekinumab disclosed in Abstract P759 was a method of treatment that was relevant for the purposes of assessing novelty.

The Delegate then went on to consider whether the specific clinical endpoints in the AU134 claims conferred novelty on the claims.  The Delegate answered this question in the negative.  While the specific clinical endpoints in the AU134 claims were new information that was not disclosed in Abstract P759, the Delegate held that these endpoints were not features that could provide a meaningful difference over what was disclosed in the prior art but were “merely supplementary information” about the measure of success which the method of administering ustekinumab was intended to achieve.

In contrast, the Delegate considered that the length of the maintenance treatment recited in claim 29 did specify the duration of the maintenance therapy and was therefore a limitation on the dosage regimen.  Consequently, the length of the maintenance treatment was a limitation on the claim and could confer novelty.

Obviousness

The Delegate considered the question of obviousness based on the common general knowledge (CGK) alone and in combination with the prior art relied on in the novelty case.

The Delegate held that Samsung had not established that, when considering the CGK alone, the skilled person would be directly led as a matter of course to select only ustekinumab to treat moderately to severely active UC in the expectation that doing so might well produce a useful alternative to the prior art.  The Delegate considered that the idiosyncrasies associated with Samsung’s expert’s experience as a practitioner in Australia led him to select ustekinumab and exclude other potential drug candidates for the hypothetical task which he addressed in his evidence.  The hypothetical task given to Samsung’s expert required him to propose a medication for the treatment or management of UC which would be a useful alternative to, or better than, the medications that were approved for use for the treatment and/or management of UC, based on information that was known and accepted and regarded to be widely known and generally accepted by other gastroenterologists (whether in Australia or overseas) working in the field of the diagnosis, treatment and management of inflammatory bowel disease before the priority date.

The Delegate, however, found that all of the AU134 claims were obvious in light of the CGK taken together with the prior art cited for lack of novelty.  The Delegate’s decision in this regard flowed directly from the Delegate’s decision that all of the AU134 claims were anticipated by one or more of the cited prior art.

Support

The Delegate applied the following three-step process in determining the issue of support:

1. Construction of the claims to determine the scope of the invention as claimed;
2. Construction of the description to determine the technical contribution to the art; and
3. Determination as to whether the claims were supported by the technical contribution to the art.

Ultimately, the Delegate held that the AU134 claims corresponded to the technical contribution to the art disclosed in the description, with the technical contribution to the art being the use of an anti-IL-12/IL-23p40 antibody having the six defined CDRs sequences (these being amino acid sequences SEQ ID NO: 1 to SEQ ID NO: 6) to bind to the common p40 subunit of IL-12 and IL-23 and thereby neutralise the cellular responses mediated by these cytokines.

Outcome and Implications

The Delgate’s decision illustrates the power of strong prior art to knock out a patent application on the grounds of lack novelty and obviousness, with all claims of the AU134 claims being held to be invalid on those grounds.  The Australian Patent Office has now formally refused AU134, as Janssen did not appeal the opposition decision to the Federal Court of Australia or propose amendments aimed at overcoming the deficiencies in the claims.

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