Health

A shift in the landscape of Australian pharmaceutical patent litigation has emerged as preliminary injunction (PI) applications, which had largely stagnated since 2021, saw renewed activity in 2025. This resurgence included two significant cases in the Federal Court, one of which involved an appeal heard in late 2025. The outcomes of these cases highlight critical distinctions in how the courts assess infringement and the balance of convenience in granting injunctions.

In September 2025, Justice Rofe dismissed a PI application from Regeneron and Bayer aimed at preventing Sandoz from launching its aflibercept biosimilar, AFQLIR®, in Regeneron Pharmaceuticals, Inc. V Sandoz Pty Ltd [2025] FCA 1067. In contrast, just a few months later, in December 2025, Justice Burley granted a PI in Janssen Pharmaceutica NV v Juno Pharmaceuticals Pty Ltd [2025] FCA 1538, stopping Juno from launching its generic paliperidone palmitate products.

The contrasting decisions signal a potential shift in the Federal Court’s recent trend of denying most PI applications over the past decade.

Injunction Refused: Sandoz’s Launch Approved

In the Regeneron case, the plaintiffs claimed infringement of a dosing regimen patent for aflibercept, a widely used drug for treating eye disorders such as diabetic macular oedema. The stakes were high, as a denial of the injunction would open a $500 million annual market in Australia for Sandoz and future biosimilar entrants.

Regeneron and Bayer asserted a strong prima facie case of infringement. However, the court focused on whether Sandoz’s product information instructed ophthalmologists in a manner that would infringe the patent. Justice Rofe found that the statements in Sandoz’s Product Information did not meet the patent claims. She noted that phrases like “one injection per month” did not equate to the claimed administration intervals of “2 to 4 weeks.”

Justice Rofe emphasized that Sandoz had no reason to believe that ophthalmologists would infringe the patent, particularly supported by expert evidence indicating that many ophthalmologists follow different treatment protocols.

Balance of Convenience Considerations

In evaluating the balance of convenience, Justice Rofe determined it did not favor granting a PI, citing the weak prima facie infringement case. She acknowledged that Sandoz’s entry into the market would lead to a 25% reduction in PBS prices, potentially harming Regeneron and Bayer financially. However, she recognized that the existing market dynamics already favored a transition to different dosages of aflibercept, which were not subject to biosimilar competition.

Justice Rofe also noted Sandoz’s first mover advantage in a conservative market where practitioners are often hesitant to switch treatments. The court deemed that broad injunctive relief would be disproportionate given the circumstances, particularly since a significant portion of aflibercept use would not infringe on the existing patent.

Following the dismissal, Regeneron and Bayer appealed the decision, but the matter was settled before the Full Court could issue a judgment.

Injunction Granted: Juno Pharmaceuticals Restricted

The Juno Pharmaceuticals case marked a distinct reversal in judicial approach regarding PIs. Janssen accused Juno of infringing its dosing regimen patent related to paliperidone palmitate products used in schizophrenia treatment. Justice Burley determined that Juno’s product information did, in fact, instruct users in a manner that would infringe Janssen’s patent.

Specifically, the PALJUNA product information advised that patients unfamiliar with oral paliperidone should first establish tolerability using Janssen’s INVEGA product, which fell under the claims of the patent. Juno contended that it wasn’t facilitating infringing conduct because the initial regimen followed Janssen’s guidelines. However, Justice Burley concluded that Juno would still be responsible for encouraging patent infringement.

Weighing the Balance of Convenience

Justice Burley found the balance of convenience favored granting the PI, highlighting the strong prima facie case of infringement. He noted that even as a typical 25% PBS price reduction was not applicable in this case, generic entry could lead to irreversible price discounting. Janssen faced potential revenue losses deemed “very substantial” if Juno entered the market.

While Juno sought to gain a first mover advantage, Burley remarked that the extent of such an advantage remained speculative. He also noted that the difficulty in calculating damages to Juno if restrained would be less complex than assessing Janssen’s damages due to patent infringement if the PI was denied.

Justice Burley acknowledged the impending expiry of the patent on December 17, 2028, indicating that a substantive trial could be completed in the second quarter of 2027, allowing for timely resolution ahead of the patent’s expiration.

Key Learnings from Recent Decisions

These cases illuminate critical considerations for pharmaceutical companies in Australia regarding PIs:

• Lack of Inventive Step: Establishing a lack of inventive step remains a challenging ground for defeating a PI, as illustrated in both cases.
• Compelling Non-infringement Arguments: Displacing a prima facie case on infringement requires robust non-infringement arguments or a strong case for lack of novelty.
• Unique Factors Matter: Unique circumstances, such as market shifts caused by the patentee or first mover advantages, can significantly influence the balance of convenience.

The contrasting outcomes of these cases raise questions about whether Juno represents a trend shift or an anomaly. As the legal landscape continues to evolve, particularly with the recent granting of a PI against Pharmacor in AstraZeneca AB & Anor v Pharmacor Pty Limited on February 16, 2026, the implications for patent litigation in the pharmaceutical sector remain significant.

As these developments unfold, stakeholders in the pharmaceutical industry should stay vigilant and prepared for further changes in judicial approaches to patent litigation.