[The IPKat] Is the tide turning for pharmaceutical patent preliminary injunctions in Australia?

[Claire Gregg]

Is the tide turning for pharmaceutical patent preliminary injunctions in Australia?

 Dr Claire Gregg Thursday, March 19, 2026 - Australia, Claire Gregg, OzKat, pharmaceutical patents, preliminary injunction

For nearly eight years, the Federal Court of Australia knocked back all preliminary injunction (PIs) sought by pharmaceutical originators. The prevailing view of the Court seemed to be that damages were adequate compensation for losses incurred by innovators resulting from generic market entry that ultimately turned out to constitute infringing conduct. So, it was a surprise to say the least when the Court granted not one but two PIs to originators in recent months.

PIs in Australia

In deciding whether to grant a PI, the factors considered by the Court are:

(1)      whether there is a prima facie case the applicant for the PI will succeed at trial; an

(2)      whether the balance of convenience weighs in favour of injunctive relief.

In relation to the first factor, the applicant for injunctive relief needs to show a sufficient likelihood of success to justify the preservation of the status quo pending trial (not necessarily that it is likely to succeed at trial). This depends on the nature of the rights being asserted, and the harm likely to flow to the applicant if the PI is not granted.

In relation to the second factor, the Court weighs the prejudice and hardship likely to be suffered by the respondent, third parties and the public generally if an injunction is granted, against the likelihood that the final relief (if granted) will adequately compensate the applicant for continuing infringement between the date of the PI hearing and the date final relief is granted.

PIs are of particular importance in the Australian pharmaceutical sector because the first registration of a generic product on the Pharmaceutical Benefits Scheme (PBS) triggers an automatic and irreversible price drop for the originator drug.

First pharma PI in nearly eight years

Injunction Kat

In Janssen Pharmaceutica NV v Juno Pharmaceuticals Pty Ltd [2025] FCA 1538, the claimed invention relates to a three-step dosing regimen for administering paliperidone palmitate to a psychiatric patient, the dosing regimen including a first loading dose and a second loading dose, followed by monthly maintenance dosing. This patent covers the dosing regimen for the Johnson & Johnson product INVEGA SUSTENNA, which is used to treat schizophrenia.

The respondent, Juno, listed two products on the Australian Register of Therapeutic Goods (ARTG) – PALJUNA MONTHLY and VALINO MONTHLY. The product information for PALJUNA MONTHLY recommends use of INVEGA SUSTENNA in the loading dose steps of the dosing regimen and PALJUNA MONTHLY as a maintenance dose only, whereas the product information for VALINO MONTHLY recommends use in all three steps of the dosing regimen. Juno notified Janssen of its intention to register these products on the PBS, which Janssen alleged threated to infringe its INVEGA SUSTENNA dosing regimen patent.

In particular, the PALJUNA MONTHLY product raised a novel question of infringement under Australian law because the product information did not recommend its use in all the dosing steps. However, the Court considered the stronger argument to be that Juno is "sanctioning, approving or countenancing a course of treatment that includes the provision of ongoing maintenance doses as part of the claimed dosing regimen".

In relation to Juno's invalidity allegations, the Court considered the arguments raised to be "arguable" at best. In contrast, on the balance of convenience question, the Court considered that Juno’s potential harm is compensable, whereas Janssen would suffer substantial and likely irreparable commercial harm if Juno entered the market before trial. Overall, the strength of Janssen's infringement case and the relevant balance of convenience factors justified granting a PI - the primary factor being the strength of Janssen’s prima facie infringement case - and the issues will ultimately be borne out at trial.

Further surprise PI decision

In AstraZeneca AB v Pharmacor Pty Ltd [2026] FCA 88, the Federal Court again granted a rare PI to an originator pharmaceutical company. In this case, the claimed invention relates to the compound dapagliflozin, which is the active pharmaceutical ingredient in AstraZeneca's product FORXIGA, which is used to treat type 2 diabetes.

The respondent, Pharmacor, listed two products on the ARTG – GLIXAFOR and PHARMACOR DAPAGLIFLOZIN. Pharmacor notified AstraZeneca of its intention to register these products on the PBS, which threatened to infringe the FORXIGA patent.

There was no dispute between the parties that Pharmacor's products fall within the scope of the claims. However, a key issue was whether the FORXIGA patent lacks novelty because the prior art discloses a generic Markush formula that includes dapagliflozin, but does not specifically identify this compound. Pharmacor sought to argue that dapagliflozin is not a valid "selection invention" because it does not meet the following criteria:

·                     there must be some substantial advantage to be secured by the use of the selected members;

·                     the whole of the selected members must possess the advantage in question;

·                     the selection must be in respect of a quality of a special character, which can fairly be said to be peculiar to the group; and

·                     the advantage possessed by the selected members must be clearly disclosed in the specification.

However, these criteria were stipulated by a patent examiner, whose comments were reproduced in the decision of the Full Federal Court in Ranbaxy Australia Pty Ltd v Warner-Lambert Co LLC [2008] FCAFC 82. As noted by the Court, these criteria do not form part of Australian law. Rather, to destroy novelty, a prior art disclosure must provide "clear and unmistakable directions to do what the patentee claims to have invented". Accordingly, the Court considered Pharmacor's novelty argument to be "arguable" but one that "does not diminish the strength of the prima facie case on infringement".

In relation to Pharmacor's inventive step case, the Court referred to the Janssen decision mentioned above and reiterated the view expressed in that decision that an allegation of lack of inventive step "is ill -suited to the objective that Pharmacor seeks to attain, which is to demonstrate weakness in the prima facie case of infringement asserted against it".

Finally, in relation to balance of convenience, the Court made a particularly poignant point at [109] as follows:

While it may be accepted that it is in the interests of the Commonwealth and the public for FORXIGA to be sold at a cheaper price (which tells against the grant of the interlocutory injunction), it must also be remembered that the grant of a patent confers a statutory monopoly which is designed to encourage and reward invention, which invention is for the benefit of all. It is therefore in the interests of the Commonwealth, and the public generally, that such invention occurs and is encouraged to continue to occur in the future. A failure to restrain a party from exploiting generic products in the circumstances of this case could have the result that the patent system in Australia is undermined with a consequential negative impact on future research and development, and upon the licensing of patented pharmaceutical products, in Australia.

Thus, having regard to the strength of AstraZeneca's infringement case, the balance of convenience was considered to weigh in favour of AstraZeneca.

Is the tide turning for PIs in Australia?

While the issues at play in Janssen and AstraZeneca will ultimately be borne out at trial, these interlocutory decisions hint at a much-needed turning of the tide in relation to pharmaceutical PIs in Australia, particularly where there is a strong prima facie case of infringement. Key issues to watch out for at trial include the question of infringement of a multi-step dosing regimen in Janssen, and the question of selection inventions in AstraZeneca.

 

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