Biosimilar Patent Battles: Australian Court Decisions Signal Shifting Landscape

Recent decisions in Australian pharmaceutical patent litigation involving aflibercept and paliperidone palmitate are offering insights into the evolving approach of the Federal Court regarding preliminary injunctions (PIs) in biosimilar cases. After a period of reluctance to grant PIs, the court appears to be reassessing its stance, with implications for both innovator and generic/biosimilar companies.

Injunction Refused: Sandoz and Aflibercept

In Regeneron Pharmaceuticals, Inc. V Sandoz Pty Ltd [1], Justice Rofe dismissed an application by Regeneron and Bayer to prevent Sandoz from launching its aflibercept biosimilar, AFQLIR®. The case centered on a patent covering a dosing regimen for aflibercept (EYLEA®), a drug used to treat eye disorders like diabetic macular oedema. A successful launch by Sandoz could open the door to a significant market opportunity, potentially valued at $500 million annually in Australia.

Regeneron and Bayer argued that Sandoz’s product information instructed ophthalmologists to administer the drug in a way that infringed the patent. However, Justice Rofe found that the language used in Sandoz’s product information – “one injection per month” or “every two months” – did not equate to the patent’s claims of “2 to 4 weeks” or “8 weeks” intervals. The court construed the patent claims strictly, noting the patentee’s specific wording.

Justice Rofe considered the balance of convenience. While acknowledging potential financial harm to Regeneron/Bayer from a 25% price reduction under the Pharmaceutical Benefits Scheme (PBS), she noted that the companies were already shifting the market by encouraging a switch to a higher dosage (8mg) with no current biosimilar competition. Sandoz’s potential first-mover advantage in the biosimilar market and the difficulty of calculating damages also factored into the decision.

The Full Court heard an appeal of this decision on October 29, 2025, but the case settled before a judgment was delivered. [2]

Injunction Granted: Juno Pharmaceuticals and Paliperidone Palmitate

In contrast to the Sandoz case, Justice Burley granted a preliminary injunction to Janssen in Janssen Pharmaceutica NV v Juno Pharmaceuticals Pty Ltd, restraining Juno from launching its generic paliperidone palmitate products. [3] This case involved a patent related to a dosing regimen for paliperidone palmitate, used in the treatment of schizophrenia.

The court found that Juno’s product information instructed patients to initiate treatment with Janssen’s INVEGA product, administered according to instructions that fell within the scope of Janssen’s patent claims. Despite Juno’s argument that it wasn’t “authorizing” infringing conduct, Justice Burley determined that Juno would be responsible for facilitating infringement.

Justice Burley also considered the balance of convenience, noting that while the typical 25% PBS price reduction didn’t apply in this case, generic entry would still lead to price discounting. He also recognized the potential for significant revenue loss for Janssen. The court acknowledged the difficulty in calculating damages to Juno if the injunction was wrongly granted, compared to calculating Janssen’s damages if it wasn’t.

Key Learnings for Pharmaceutical Companies

• Inventive Step Challenges Remain Demanding: Successfully challenging a patent based on lack of inventive step at the preliminary injunction stage remains a high hurdle.
• Strong Infringement or Invalidity Arguments are Crucial: Displacing a prima facie case of infringement requires a compelling non-infringement argument or a strong case for patent invalidity.
• Expert Evidence Matters: The position of expert witnesses on infringement issues can significantly influence the court’s decision. Robust evidence addressing the nuances of the competing infringement positions is essential.
• Balance of Convenience Factors: A unique factor, such as the patentee shifting the market themselves, can be material to the balance of convenience assessment.
• Time to Patent Expiry: The remaining time until patent expiry is a relevant consideration, as a PI may be akin to final relief if a trial cannot be completed before expiry.

The recent decisions, along with a February 16, 2026, decision granting a PI against Pharmacor in AstraZeneca AB & Anor v Pharmacor Pty Limited, [4] suggest a potential shift in the Federal Court’s approach to preliminary injunctions in pharmaceutical cases. Further developments will be closely watched by companies operating in this space.