[The IPKat] Clinical trials and tribulations

[Claire Gregg]

Clinical trials and tribulations

 Dr Claire Gregg Tuesday, January 13, 2026 - Australia, Claire Gregg, clinical trials, OzKat, patents

Navigating the interplay between patents and clinical trial disclosures is becoming increasingly challenging worldwide. Following the recent EPO Board of Appeal decision in T0883/23, which found that a study protocol is not "the same" as a therapeutic effect for the purpose of claiming priority (IPKat), this OzKat takes a closer look at the effect of clinical trial disclosures on validity in Australia.

Priority and sufficiency

In Australia, the test for priority is a sufficiency test: the earlier application(s) must disclose "the invention in the claim in a manner that is clear enough and complete enough for the invention to be performed by a person skilled in the relevant art" (Patents Act 1990 (Cth), s 43(2A)(b)). While the wording of Art 87(1) EPC, that the earlier application must be "in respect of the same invention" is absent from the Australian Patents Act, the Federal Court has confirmed that the earlier application must nonetheless meet this requirement for priority entitlement to be satisfied (ToolGen Incorporated v Fisher (No 2) [2023] FCA 794).

The Australian courts have not yet considered the requirement for sufficiency in the context of a clinical trial disclosure (either for the purpose of claiming priority or for assessing internal validity). However, the Explanatory Memorandum accompanying the legislation that introduced the current sufficiency test for priority and internal validity made it clear that the purpose of these provisions was to "align the disclosure requirement with that applying in other jurisdictions", including the UK and Europe. Therefore, it is likely we will see patent challengers seek to rely on T0883/23 to mount similar challenges in Australia.

Novelty

In Australia, second medical uses are typically claimed using method of treatment and Swiss-style claims, as EPC2000 style "for use" claims are considered non-limiting. As distinct from EPC2000 claims, which are characterised by a therapeutic effect, method of treatment and Swiss-style claims are characterised by a therapeutic purpose. This means novelty can be destroyed if the prior art discloses an intention to treat the claimed condition, even if a therapeutic effect is not achieved or disclosed. Importantly, however, inherent anticipation does not apply where the claim is to the use of "a known compound for a hitherto unknown and unexpected, but nevertheless useful, therapeutic use" (AstraZeneca AB v Apotex Pty Ltd [2014] FCAFC 99).

Clinical Trial Kat

The courts have previously found that a Phase I clinical trial disclosure (Bristol-Myers Squibb Company v F H Faulding & Co Limited [2000] FCA 316) and patient consent forms used in Phase II clinical trials (InterPharma Pty Ltd v Hospira, Inc (No 3) [2017] FCA 1536) were not novelty destroying in the relevant circumstances. In contrast, a Phase II disclosure containing an untested "reasoned hypothesis" that the study will work was found to be novelty destroying (Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd [2020] FCAFC 116). In particular, in Mylan, the Phase II clinical trial disclosure set out a scientific rationale as to why the drug would work; therefore, its administration in the trial was considered "treatment", rather than merely testing a hypothesis.

A recent decision by the Australian Patent Office considered an untested Phase III clinical trial protocol summary that merely disclosed a hypothesis to be tested to be novelty destroying (Samsung Bioepis AU Pty Ltd v Janssen Biotech, Inc. [2025] APO 32). However, this decision is not binding, and it remains to be seen how the courts will deal with such a disclosure.

Inventive step

Much like in the UK, the test for inventive step in Australia requires not only that the invention be obvious to try, but also that the skilled person have a reasonable expectation of success. In Sandoz AG v Bayer Intellectual Property GmbH [2024] FCAFC 135, the Full Federal Court overturned a decision by the trial judge, and found that two of Bayer’s XARELTO (rivaroxaban) patents lacked an inventive step. The Full Court was concerned with whether the claimed compounds were obvious in light of the patentee’s own prior patent publication, WO 01/47919, which identified rivaroxaban as being a "very particularly preferred" compound for the treatment and prophylaxis of thromboembolic disorders and provided in vitro results in support of this conclusion.

In relation to "reasonable expectation of success", the Full Court considered that WO 919 identified rivaroxaban as the lead candidate for treating thromboembolic disorders and, in the absence of evidence that there was a "particular problem, difficulty or issue overcome" in taking that compound through pre-clinical and clinical trials, the claims lacked inventive step. This effectively reduced the test for inventive step to an "obvious to try" test.

Particularly problematic was the Full Court's reasoning that "the need to carry out clinical trials and other tests in order to obtain relevant data can be regarded as routine work consistent with a finding of obviousness". Further, the Full Court stated: "Having regard to the risks and uncertainties associated with the drug development process on the facts of this case, one would not expect the person skilled in the art to even commence pre-clinical trials if such an expectation was absent".

Unfortunately, the High Court refused to allow an appeal.

The clinical trial conundrum

The requirement to publish details relating to clinical trials before they commence versus the need for sufficient data for both priority and internal validity presents a particular conundrum for pharmaceutical companies seeking to patent their therapeutic inventions. Even scant details can be problematic where second medical use claims are characterised by a "therapeutic purpose" standard and even clinical trials are considered "routine" in the absence of evidence to the contrary.

Although the case law is less developed in Australia than in the UK and Europe, the Australia courts are prone to following case law from those jurisdictions, particularly in relation to sufficiency and support. That said, medical use inventions do not require a therapeutic effect to be achieved in Australia, which could lead to nuances in the way the law is applied. Whether or not this will factor into the courts' reliance on T0883/23 is yet to be seen, or whether it will create a tension between novelty and sufficiency for patent challengers. However, including at least in vitro data in an earlier (priority) application – to be filed before any clinical trial disclosure is published – is nonetheless advisable.

 

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