Why have a Swiss-form claim in an Australian patent when methods of medical treatment are patentable? In a recent first instance decision of the Federal Court of Australia, Swiss-form claims have been held to be method claims, that is, methods of manufacturing a medicament and not methods of medical treatment. If this construction of Swiss-form claims is upheld, Swiss-form claims may provide different scope to their mirroring method of medical treatment claims.
The Swiss-form claim structure was adopted in Australia after its development in Europe. Swiss-form claims have been granted alongside method of medical treatment claims for years. However, it is not yet settled under Australian law:
- if Swiss-form claims and their mirroring methods of medical treatment claims have the same scope;
- if different evidence is required to prove infringement of each claim type; or
- if damages for infringement of each claim type would be calculated differently.
The recent Federal Court decision1 sheds some light on these issues. Unfortunately, a first instance decision cannot put these matters to rest.
Second medical use claim types
Attorneys commonly use the term “Swiss-form claim” to refer to claims of the following structure “use of compound [X] in the manufacture of a medicament for [a new therapeutic use]”. This claim type may be used to claim a second medical use of a compound in jurisdictions where methods of medical treatment are not patentable, for example, New Zealand. Swiss-form claims were also used in Europe prior to the switch under EPC 2000 to product by process claims, ie, claims for a compound only when it is used in a specified way.
In Australia, all three claim types are used:
- Methods of medical treatment;
- Swiss-form claims; and
- Product by process claims.
Therefore, the question in Australia is which one or more of these claim types is the best choice?
AU 2005201772 (AU ‘772) included both a Swiss-form and a method of medical treatment claim for the same invention.
Claim 1 – Swiss-form
Use of a cabostyril compound of [structural formula] or a pharmaceutically acceptable salt or solvate thereof, for the production of a medicament, effective in the treatment of disorders of the central nervous system associated with [the] 5-HT1A receptor subtype [further details on the relevant disorder].
Claim 7 – Method of medical treatment
A method for treating a patient suffering from disorders of the central nervous system associated with [the] 5-HT1A receptor sub-type [further details on the relevant disorder] comprising administering to said patient a therapeutically effective amount of a carbostyril compound of [structural formula] or a pharmaceutically acceptable salt or solvate thereof.
Is a Swiss-form claim a method, product or something new?
The decision considered if a Swiss-form claim is:
- a method claim; or
- something that is neither a method nor product claim.
Justice Yates held that Swiss-form claims were appropriately categorised as method claims. However, Justice Yates did not treat the Swiss-form claim as another format for a method of medical treatment claim. Instead, Justice Yates followed the Australian literal approach to claim construction to find the Swiss-form claim was directed to a method of making a medicament and not a method of medical treatment.
What is the effect of the new therapeutic use?
If a Swiss-form claim is a method of manufacture of a medicament, the next question is what is the function of the claim language specifying the medicament is for treating a specific condition?
Justice Yates mentions that:
- the therapeutic use qualifies the monopoly;
- the therapeutic use of the medicament will usually be manifest from the marketing approval and registration that has been granted for it;
- a failure to advertise or promote the medicament for the claimed use may not avoid infringement; and
- the question is whether, objectively ascertained, the medicament that results from the claimed method is one that has the therapeutic use defined in the claim.
Given Australian literal claim construction, a tension has always existed around whether a particular indication is inherent to a product or qualifies the product to provide novelty and inventive step.
It is not entirely clear from the judgment:
- whether showing the therapeutic use is an inherent feature of the medicament claimed in the Swiss-form claim will be enough to show the medicament “has the therapeutic use”; or
- if something more is required for a medicament to have a therapeutic use, such as, evidence the medicament will be put to the therapeutic use or evidence the supplier of the medicament has a reasonable expectation that the medicament will be put to the therapeutic use.
Clarifying whether Swiss-form claims require the medicament to be suitable for the claimed use or actually applied to the claimed use has important consequences for novelty and infringement.
What about patentable subject matter?
The decision expressly avoided considering if Swiss-form claims were patentable subject matter under Australian law. As methods of medical treatment have been confirmed by the High Court of Australia as patentable subject matter, patentees can have greater confidence in the ultimate validity of method of medical treatment claims than Swiss-form claims.
For the moment, there is potential benefit in including Swiss-form claims in an Australian patent to provide a claim structure with potentially different scope to its related method of medical treatment claim.