Pharmaceutical patent preliminary injunction drought ends in Australia
For almost eight years, pharmaceutical originators faced an unbroken run of defeats when seeking preliminary injunctions (PIs) in the Federal Court of Australia. The prevailing judicial approach appeared to be that monetary damages were an adequate remedy for losses suffered by innovators arising from generic market entry, even where that entry later proved to be infringing. Against that backdrop, the recent grant of two PIs to originator companies is a significant and unexpected development, and may mark a turning point in the Australian pharmaceutical injunction landscape.
Preliminary injunctions in Australia
In deciding whether to grant a PI, the Federal Court applies a two-stage test. First, the applicant must establish a prima facie case that it will succeed at trial. Second, the Court must be satisfied that the balance of convenience favours the grant of injunctive relief.
The prima facie inquiry does not require a finding that success at trial is probable. Rather, the applicant must demonstrate a sufficient likelihood of success to justify preserving the status quo pending final determination. This assessment depends on the nature of the rights asserted and the harm likely to flow if interlocutory relief is refused.
The balance of convenience requires the Court to weigh the prejudice or hardship likely to be suffered by the respondent, third parties and the public if an injunction is granted, against whether final relief would adequately compensate the applicant for harm caused by continued infringement before trial.
PIs are of particular importance in the pharmaceutical context. Once a generic product is first listed on the Pharmaceutical Benefits Scheme (PBS), an automatic and irreversible price reduction is triggered for the originator drug. The commercial consequences of generic entry are therefore immediate, profound and often incapable of being fully remedied by damages alone.
First pharmaceutical PI in nearly eight years
The Federal Court’s decision In Janssen Pharmaceutica NV v Juno Pharmaceuticals Pty Ltd [2025] FCA 1538 marked the first grant of a pharmaceutical PI in almost eight years. The patent concerned a three-step dosing regimen for administering paliperidone palmitate involving unequal first and second loading doses, followed by monthly maintenance dosing. The patent covers the dosing regimen used for Johnson & Johnson’s schizophrenia treatment INVEGA SUSTENNA.
Juno listed two products on the Australian Register of Therapeutic Goods (ARTG): PALJUNA MONTHLY and VALINO MONTHLY. The PALJUNA MONTHLY product information recommended use of INVEGA SUSTENNA for loading doses and PALJUNA MONTHLY for maintenance dosing only. By contrast, VALINO MONTHLY was recommended for all three dosing steps. Juno notified Janssen of its intention to list these products on the PBS, prompting allegations of threatened infringement.
PALJUNA MONTHLY raised a novel infringement issue because it did not expressly recommend use in all steps of the claimed regimen. Nevertheless, the Court considered Janssen to have a strong argument that Juno was "sanctioning, approving or countenancing a course of treatment that includes the provision of ongoing maintenance doses as part of [the claimed dosing regimen]". In contrast, Juno’s invalidity arguments were considered arguable at best.
On the balance of convenience, the Court accepted that any harm suffered by Juno was compensable, whereas Janssen faced substantial and likely irreparable commercial harm if generic entry occurred before trial. Thus, the strength of Janssen’s case, particularly its prima facie infringement case was therefore decisive in granting of the PI.
Further surprising PI decision
The Court again granted a PI in AstraZeneca AB v Pharmacor Pty Ltd [2026] FCA 88. The patent related to dapagliflozin, the active ingredient in AstraZeneca’s type 2 diabetes treatment FORXIGA. Pharmacor listed two dapagliflozin products on the ARTG – GLIXAFOR and PHARMACOR DAPAGLIFLOZIN and notified AstraZeneca of its intention to list them on the PBS.
There was no dispute that Pharmacor’s products fell within the scope of the patent claims. Instead, Pharmacor argued the patent lacked novelty because the prior art disclosed a broad Markush formula encompassing dapagliflozin, even though it did not expressly identify the compound. Pharmacor contended that dapagliflozin was not a valid selection invention, relying on criteria articulated by a patent examiner. The Court rejected this approach, noting that those criteria do not form part of Australian law. Rather, novelty is only destroyed where the prior art provides clear and unmistakable directions to make or use the claimed invention. While Pharmacor’s novelty challenge was considered arguable, it did not materially weaken AstraZeneca’s prima facie infringement case.
The Court was similarly dismissive of Pharmacor’s inventive step argument, reiterating observations made in Janssen that such arguments are "ill-suited" to undermining a strong prima facie infringement case at the interlocutory stage.
On the balance of convenience, the Court acknowledged the public interest in cheaper medicines, but emphasised that patents confer a statutory monopoly intended to promote and reward innovation. Failure to restrain generic entry in these circumstances risked undermining the patent system, with negative implications for research, development, and licensing in Australia. Accordingly, the balance of convenience also favoured AstraZeneca.
What next?
Although the ultimate outcomes in Janssen and AstraZeneca will be determined at trial, these interlocutory decisions suggest a renewed willingness by the Federal Court to grant pharmaceutical PIs, particularly where there is a strong prima facie case of infringement. Key issues to watch include the novel question of infringement of multi-step dosing regimens in Janssen, and the application of novelty principles to selection inventions in AstraZeneca.
Authored by Dr Claire Gregg of Davies Collison Cave.
Click to connect
