Traditional Swiss-style claims provide a unique form of protection for pharmaceutical patentees against the authorised use of an active agent in the manufacture of a medicament for a new therapeutic use. Such second-medical use claims are particularly important in New Zealand, where methods of treating humans are excluded from patentability.1 A number of recent decisions issued by the New Zealand Patent Office (IPONZ) provide useful guidance on the allowability of Swiss-style claims that do not fit the traditional format in New Zealand.
The fiction of Swiss-style claims
Swiss-style claims were first conceived in Europe in the 1980s in response to a need to protect novel therapeutic uses of known compounds in a legislative framework that excluded method of medical treatment claims from patentability. Such claims are often referred to as a "legal fiction" because their novelty is derived solely from the discovery of a new therapeutic use of a known compound; it is not necessary for the product or the process of manufacture to be novel. While claims in Swiss-style format were superseded by "for use" claims in Europe when major revisions to the European Patent Convention were implemented in 2000, they are still the preferred second medical use format in a number of jurisdictions, including New Zealand.
The New Zealand Court of Appeals affirmed the allowability of Swiss-style claims in Pharmac,2 stating "there can be invention and novelty in the discovery of unrecognised properties of known pharmaceutical compounds". Thus, traditional Swiss-style claims of the form "Use of [active agent] in the manufacture of a medicament for the treatment of [therapeutic indication]" are allowable in New Zealand where the active agent has not previously been used to treat the therapeutic indication. IPONZ has also found that the novelty of Swiss-style claims can reside in new dosage forms, modes of administration, treatment regimens or patient groups.3
Swiss-style claims differ in scope to method of treatment claims. Whereas method of treatment claims are directly infringed by medical professionals in the treatment of patients, a Swiss-type claim is "directed to the manufacture of the medicament with the intention of a specified medical use, but does not extend to the actual method of treatment. It is therefore limited to the preparation and sale of a product for the purpose of carrying out a specific medical treatment".4 While not yet tested before a New Zealand court, the Full Federal Court of Australia has confirmed that Swiss-style claims are only infringed when the medicament is manufactured for the specified therapeutic purpose, which involves consideration of a number of factors discussed here.5
Functional language in Swiss-style claims
A recent decision by IPONZ, Ardelyx Inc.  NZIPOPAT 7 (Ardelyx), confirmed that the active agent in a Swiss-style claim may be defined solely in functional terms.6 DCC represented Ardelyx Inc. before IPONZ.
The Ardelyx decision concerned the following Swiss-style claim:
Use of a compound in the manufacture of a medicament for inhibiting phosphate uptake in the gastrointestinal tract of a patient with hyperphosphatemia, wherein said compound is an NHE3 inhibitor. [emphasis added; proviso omitted]
The Examiner objected to the above claim as lacking clarity and support on the basis that the active agent was defined in a "vague and speculative manner" and has an "essentially unlimited scope of compounds". However, the Assistant Commissioner considered the claim to be "as precise and exact as needed to clearly define the invention".
According to the Assistant Commissioner, in addition to the situation in Pharmac where the invention and novelty resided in the discovery of an unrecognised property of known pharmaceutical compounds, "there can be invention and novelty in the discovery of an unrecognised interaction between chemical inhibition of a particular protein present on certain cell types in the gastro-intestinal tract and the inhibition of phosphate uptake by those cells". In accordance with Pharmac, such circumstances give rise to an obligation to make patent protection available to the extent that it is compatible with the prohibition on methods of medical treatment.
In reaching the decision in Ardelyx, the Assistant Commissioner took account of the state of the law in Europe in relation to the use of functional features in second-medical use claims. In particular, the German Federal Court of Justice (FCJ) found a second medical use claim in which the active agent was defined solely in functional terms – and where the specification only provided four examples of active agents having the recited functional feature – to be clear and sufficiently disclosed.7 The key finding of the FCJ, with which the Assistant Commissioner appeared to agree, are:
- The applicant may claim certain generalisations of the exemplified embodiments, provided that doing so takes account of the legitimate desire to cover the invention in its entirety;
- The scope of protection sought should not extend beyond what would appear to a person skilled in the art from the specification as a whole to be the most generalised technical teaching by which the problem underlying the invention is solved; and
- Describing a group of compounds according to their function is not precluded by the fact that they may encompass compounds yet to be known, or that such compounds may require inventive activity to produce.
The formulation of Swiss-style claims
Two other recent decisions by IPONZ – Taiho Pharmaceutical Co. Ltd  NZIPOPAT 5 (Taiho 1) and Taiho Pharmaceutical Co., Ltd.  NZIPOPAT 1 (Taiho 2) – highlight that Swiss-style claims must be formulated with care to ensure they are allowable in New Zealand.
Taiho 1 concerned a Swiss-style claims directed to:
Use of a combination drug comprising trifluridine (FTD) and tipiracil hydrochloride (TPI) at a molar ratio of 1:0.5 for the manufacture of [a medicament for the prevention or treatment of cancer in a subject OR an antitumor effect enhancer to enhance the antitumor effect of an antibody in a cancer patient], wherein the medicament comprises:
the combination drug which is formulated for co-administration at a dose of from 35 to 70 mg/m2/day as FTD with an antibody selected from the group consisting of bevacizumab, cetuximab and panitumumab at a [specified dose]; and wherein the cancer is colorectal cancer or breast cancer. [emphasis added]
Relevantly, the use of the FTD/TPI combination drug and each of the antibodies was separately known in the art for the treatment of patients with either or both specified therapeutic indications. Thus, according to the Assistant Commissioner, the "nub of the invention" was the co-administration of all three active agents, and "a Swiss-style claim that is commensurable with the disclosed method of therapy should require the use of both drugs (the combination drug and the anti-body) in the manufacture of medicaments for the treatment of breast and colorectal cancer". The combination drug being "formulated for" co-administration with the antibody was construed as the combination merely being suitable for co-administration with the antibody.
In contrast, the Assistant Commissioner referred to another IPONZ decision in which the Swiss-style claims at issue recited that the medicament was "formulated for" administration in conjunction with the known drug ritonavir.8 In that case, the claims were allowable because the active agent present in the medicament was novel. However, corresponding Swiss-style claims in which the medicament contained ritonavir and was formulated for administration in conjunction with the new active agent, were not allowable because they were not directed to a new use of ritonavir.
The Assistant Commissioner also noted in Taiho 1 that Swiss-style claims in which the medicament was for a known therapeutic use of the active agent, but which was "adapted for" or "formulated for" administration in a novel dosage form, mode of administration or dosage regimen, have been allowed where they "relate to more than additional information about an existing and known medical use which could be put into effect using known dosage forms"9 or overcome or alleviate a problem associated with known modes of administration or dosage regimens.10 It was also noted that the novelty of a Swiss-style claim can reside in a specific patient group where that group has not previously been shown to be sensitive to the specified treatment.11
Taiho 2 concerned, inter alia, the clarity of the following Swiss-style claim:
Use of trifluridine and tipiracil hydrochloride in a molar ratio of 1:0.5 in the preparation of an antitumor medicament for the treatment of solid cancers,
wherein the antitumor medicament is adapted to administer trifluridine and tipiracil hydrochloride at a dose in the range of 35 to 70 mg/m2 /day, and
wherein the antitumor medicament is adapted to administer trifluridine and tipiracil hydrochloride in combination with irinotecan hydrochloride hydrate at a dose in the range of 45 to 130 mg/m2 /day. [emphasis added]
Relevantly, the FTD/TPI combination was known in the art for use in the treatment of solid cancers. The invention was said to reside in the discovery that the combination of FTD, TPI and irinotecan hydrochloride hydrate, when administered in the recited ratio and dosages, provides "remarkable" antitumor effects with few side effects. The Assistant Commissioner agreed with the Examiner that the above claim "is not clearly directed to what the applicant has discovered" and directed that the claim be amended to include all three active agents in the manufacture of the medicament.
Another aspect of the Taiho 2 decision relating to double patenting was discussed in our article here.
The Ardelyx decision is good news for pharmaceutical applicants as it establishes that unduly restricting the scope of Swiss-style claims by defining the active agent in structural terms is improper where the invention legitimately resides in a newly discovered connection between a biological function and a therapeutic outcome.
The Taiho 1 and Taiho 2 decisions highlight the importance of careful claim drafting to obtaining allowable Swiss-style claims in New Zealand. For non-traditional Swiss-style claims it is important to consider what the "nub of the invention" is. For example, where the invention resides in a particular active agent or a combination of known active agents, the Taiho decisions suggest those active agents should be included in the manufacture of the medicament. This is inconsistent with the purpose for which Swiss-style claims were introduced and how they have been construed in other jurisdictions.
In particular, the Taiho decisions may be problematic for applicants seeking to protect combination therapies where the active agents are provided in separate dosage forms. This could give rise to a situation where the applicant's claims do not adequately protect their invention or where their invention cannot be protected in New Zealand because one or more of the dosage forms is manufactured by a third party (e.g., because one of the actives is protected by a third party patent).
There is also an inconsistency between the Taiho decisions, in which the terms "formulated for" and "adapted for" were considered non-limiting, and the earlier decisions by IPONZ in which the thing the medicament was formulated for was the "nub of the invention" and the novelty conferring feature, such as a new dosage form, mode of administration or dosage regimen that provides a surprising result or overcomes or alleviates a problem associated with existing drugs for the same therapeutic use. In such circumstances, our usual practice to avoid potentially non-limiting terms like "formulated for" and "adapted for" is to recite, for example, "wherein treating [therapeutic indication] comprises [new dosage form, mode of administration or dosage regimen]".
Whether such language would also be effective in limiting the invention to co-administration of combinations of known active agents without requiring each active agent to be used in the manufacture of the medicament remains to be seen and it is likely the New Zealand courts will need to deal with this issue at some stage in the future.
1. Patents Act 2013, s 16(2)
2. Pharmaceutical Management Agency Ltd v The Commissioner of Patents  NZCA 330
3. Merck & co. Inc. v Arrow Pharmaceuticals (NZ) Limited  NZIPOPAT 3 (31 January 2006); Genetech Inc and Washington University  NZIPOPAT 1; Epicept Corporation  NZIPOPAT 29; Astrazeneca AB  NZIPOPAT 23
4. Distillers Co Ltd's Application (1953) 70 RPC 221
5. Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd  FCAFC 116
6. DCC represented the applicant, Ardelyx, Inc., before IPONZ.
7. German Federal Court of Justice decision X ZB 8/12
8. Abbott Laboratories  NZIPOPAT 16
9. Merck & co. Inc. v Arrow Pharmaceuticals (NZ) Limited  NZIPOPAT 3
10. Genetech Inc and Washington University  NZIPOPAT 1
11. Astrazeneca AB  NZIPOPAT 23
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