Case Summary: Sun Pharma ANZ Pty Ltd v Otsuka Pharmaceutical Co Ltd [2025] FCA 44

Key Facts

• This case concerned Australian Patent No. 2004285448 owned by Otsuka Pharmaceutical Co., Ltd for "Controlled release sterile injectable aripiprazole formulation and method"
• The patent describes controlled release formulations containing aripiprazole (an antipsychotic agent) used to treat schizophrenia and bipolar I disorder
• In 2014, Otsuka was granted an extension of term until 25 July 2029
• Sun Pharma sought to have the extension removed from the Patent Register, arguing it was wrongly granted
• Sun Pharma planned to launch a generic version of Otsuka's ABILIFY MAINTENA product on 1 April 2025

Issues

1. Whether the asserted "pharmaceutical substances per se" satisfied the requirements under s 70 of the Patents Act 1990 (Cth) for a valid patent term extension
2. Whether the eight relevant claims (the "PTE Claims") were valid under ss 40(2)(b) and 40(3) of the Patents Act

Summary of Case Law

A list of the types of claims involving a pharmaceutical substances per se that are not eligible for PTE includes:

1. a pharmaceutical substance that forms part of a method or process;
2. an existing pharmaceutical substance prepared by a new and inventive process;
3. a pharmaceutical substance per se when produced by a particular process; and
4. a new and inventive method of using an existing pharmaceutical substance.

Decision

In this case, Justice Downes found the patent term extension invalid and revoked the PTE Claims on the following grounds:

1. Most of the asserted pharmaceutical substances per se failed to "in substance fall within the scope of the claim or claims" as required by s 70(2)(a) because they did not contain all essential integers of the claims.
2. The PTE Claims were invalid for:
   • Lack of clarity under s 40(3) - The claims contained limitations by result (release periods of "at least one week" or "at least two weeks") but failed to provide a workable standard to determine whether formulations met these limitations
   • Lack of definition under s 40(2)(b) - The person skilled in the art could not determine with certainty whether formulations would fall within the claimed boundaries

Key Legal Principles

• A pharmaceutical substance must take all of the integers of a claim to "fall within the scope" of that claim under s 70(2)(a)
• When claims are limited by result, the specification must enable the skilled addressee to determine whether particular embodiments achieve that result
• For claims limited by result, testing to determine whether the result is achieved must be straightforward and routine, not onerous or unreliable

Significance

Therefore the case affirms and clarifies previous Full Court authorities on patent term extensions, particularly:

• The "per se" requirement under s 70(2)(a) requires the pharmaceutical substance to take all essential integers of the relevant claim
• Following Cipla Australia Pty Ltd v Novo Nordisk A/S [2024] FCA 1414, formulations can qualify as "pharmaceutical substances" for patent term extensions
• However, claims for such formulations must still satisfy the clarity and definition requirements of ss 40(2)(b) and 40(3)

The decision highlights the importance of clearly defining the scope of claims, particularly when those claims include limitations by result that require experimentation to determine whether particular embodiments fall within the claim scope.