This article was first published in the 2023 Pharmaceutical Patent Review.
Patent term extensions (PTEs) can be of great commercial importance, and in recent years have become of particular interest in Australian pharmaceutical patent law following a number of Federal Court decisions clarifying the circumstances in which PTEs may be available.
We provide here a summary of the requirements and some recent
Federal Court decisions in this area.
Under Australian patent law, it is possible to apply for a PTE of
up to 5 years for a standard patent that claims a pharmaceutical
substance, in recognition of the exceptionally long time and
regulatory requirements involved in developing and commercialising
a new pharmaceutical substance.
As set out in section 70 of the Patents Act 1990 (Cth), a patent is eligible for PTE:
- where the claims of the patent encompass:
- Pharmaceutical substance(s) per se; or
- Pharmaceutical substance(s) produced bY recombinant DNA technology; and
- where that pharmaceutical substance is included in goods which have received regulatory approval at least five years following the effective date of the patent.
The application for PTE must be made in the "prescribed manner" which includes providing evidence to show that the goods containing the substance are currently included in the Australian Register of Therapeutic Goods (ARTG) and submitting the application for PTE within six months of the earliest inclusion in the ARTG of goods containing the pharmaceutical substance, or grant of the patent, whichever is later.
Eligibility considerations – subject matter
Except for substances produced by a process involving the use of recombinant DNA technology, an extension of term is only available in respect of a "pharmaceutical substance per se" being within the scope of a claim of the patent. The use of the term "per se" requires the claim to the substance to be unqualified by process, temporal, or environmental, components (Boehringer Ingelheim International v Commissioner of Patents [2000] FCA 1918).
Patents that claim pharmaceutical substances when produced by a particular process (product by process claims) will not be eligible (unless that process involves the use of recombinant DNA technology). In limited circumstances, a substance could be new and inventive but can only be defined by reference to the process in which it was made (for example, compound X obtainable by process Y) because the chemical structure or composition is undetermined. In such circumstances, a claim which defines the substance by reference to such method steps would be regarded as a claim to the substance per se (see Zentaris AG [2002] APO 14, and Pharmacia Italia SpA v Mayne Pharma Pty Ltd [2006] FCA).
Additionally, case law has established that pharmaceutical compositions (formulations) comprising a specified amount of an active ingredient and other components (excipients), where the mixture provides a physico-chemical interaction within the human body, can be eligible for PTE (see iCeutica Pty Ltd [2018] APO 76 and Spirit Pharmaceuticals Pty Ltd v Mundipharma Pty Ltd [2013] FCA 658). In the Mundipharma case, this extended to a slow release formulation.
Claims which limit the use of a known substance to a particular environment, for example claims drawn to the use of pharmaceutical substances when used in a new and inventive method of treatment, are not considered to be claims to pharmaceutical substances per se (see Commissioner of Patents v AbbVie Biotechnology Ltd [2017] FCAFC 129).
In a more recent Federal Court decision, Biogen International GmbH v Pharmacor Pty Ltd [2021] FCA 1591 ("Biogen"), which involved a disputed PTE, Biogen had sought an interlocutory injunction against Pharmacor. Pharmacor argued that a PTE granted on the basis of EPC2000 claims in the format "Substance X for use in the treatment of disease Y" was invalid as the claim was not to a pharmaceutical substance per se. The Federal Court was sympathetic to this position and considered that there was "a sufficiently strong prospect" that the PTE had been "wrongly granted" (Biogen at [139]) and ultimately declined to grant an injunction.
This position diverges from the construction of such claims routinely adopted by the Australian Patent Office (i.e. a product merely suitable for but not limited to the specified use). Unfortunately, this issue was not finally determined on account of settlement of the litigation. However, the decision together with advice in the Australian Patent Examiner's Manual suggests that a claim to "substance X for use ...." may not define a pharmaceutical substance per se that may support a PTE.
Eligibility considerations – first regulatory approval date
Under section 70(3) of the Patents Act 1990 (Cth), in order to be eligible for a PTE the period beginning on the date of the patent and ending on the first regulatory approval date for the pharmaceutical substance must be at least 5 years.
In two appeal judgements handed down concurrently in March 2022 (Commissioner of Patents v Ono Pharmaceutical Co. Ltd [2022] FCAFC 39 (Ono) and Merck Sharp & Dohme Corp. v Sandoz Pty Ltd [2022] FCAFC 40 (MSD)), the Full Federal Court has clarified that a PTE for a patent should be based on the earliest Australian regulatory approval date of a pharmaceutical substance which is disclosed and claimed in the patent, irrespective of whether the substance was developed by the patentee or a competitor.
In Ono, the claims of the patent encompassed two pharmaceutical substances, one belonging to the patentee (Opdivo®: registered later and afforded a longer extension), and the other belonging to a third party (Keytruda®: registered earlier and requiring an extension of time in order to timely file the PTE application). In MSD the claims of the patent encompassed two pharmaceutical substances both developed and registered by the patentee (Januvia® (sitagliptin alone): registered first and within 5 years of the date of the patent), (and Janumet® sitagliptin and metformin combination): registered (later than 5 years from the patent date).
In both decisions, it was held that the goods which were approved first were those upon which the PTE must be based. Significantly, in Ono and MSD the Full Federal Court confirmed that the language of the relevant provisions refers to the first regulatory approval date in respect of any of the pharmaceutical substances which may be disclosed and claimed in the respective patent. Accordingly, it is not open to the patentee to distinguish between its own goods and those developed by a third party, nor can a patentee exclude from consideration or nominate for itself the goods upon which a PTE is to be based, where more than one product falls within the scope of its patent. It is also clear from MSD that if the product the subject of the first regulatory approval is registered within 5 years of the patent date, no PTE will be available for it or any subsequent product falling within the patent scope.
Interestingly, Ono's alternative PTE application filed for AU 2011203119 on the basis of Keytruda® was recently granted, confirming the position that it is possible to obtain a PTE based on a third party's product.
Practical implications
Claims defining a pharmaceutical substance "for use" require careful consideration and may not be eligible to support a PTE or render any resultant PTE susceptible to challenge.
An application for PTE must be based on the broadest reading of the claim set as a whole. Where the claims of a patent to be extended cover more than one active ingredient, they should also be cross-checked against any goods entered into the ARTG to determine what registered goods are encompassed by the claims, including those of unrelated third parties.
It is advisable to consider filing one or more divisional applications during prosecution so that individual pharmaceutical substances (that are intended to be ARTG registered) are quarantined in separate applications. Proceeding in this way will avoid an earlier registration in respect of one substance precluding a PTE based on later registered goods in respect of a different substance.
Where it is not possible to file a divisional application, patentees may consider pre-emptively filing amendments to exclude earlier ARTG registered goods if appropriate, in order to facilitate eligibility and allowance of a PTE.
For further assistance
If you have questions or require assistance with your patent(s), we have specialist pharmaceutical experts working across Australia and Asia who can assist in over 25 jurisdictions.
Reach out to the team for a discussion.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.