Most practitioners would agree that Swiss-style claims are not their favourite claim format. Swiss-style claims can be difficult to formulate or construe, particularly if the medical use in question is more complicated, such a combination treatment or a specific dosage regimen.
In New Zealand, where methods of medical treatment of humans are excluded from patentability, the Court of Appeal confirmed in Pharmaceutical Management Agency Ltd v Commissioner of Patents  NZCA 330 (Pharmac) that medical uses may be claimed using Swiss-style format.
A recent decision of the Intellectual Property Office of New Zealand (IPONZ) has highlighted one of the difficulties relating to formulating and construing Swiss-style claims.
In Taiho Pharmaceutical Co., Ltd.  NZIPOPAT 1, the Commissioner considered the clarity of the following Swiss-style claim:
1. Use of trifluridine and tipiracil hydrochloride…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 in combination with irinotecan hydrochloride hydrate…
The inventors had discovered that a combination of three drugs: trifluridine, tipiracil, and irinotecan, was particularly useful for treating solid tumours when administered at certain dosages. In the specification, a dosage regimen is described (and exemplified in mice) where a ‘combination drug’ (i.e. an admixture) of trifluridine and tipiracil in a specific ratio is administered on certain days, and irinotecan is (separately) administered on other days. It would appear to be consistent then, that in the claims only trifluridine and tipiracil are included in the ‘medicament’, which is administered in combination with irinotecan.
However, the Commissioner considered that in a Swiss-style claim, it is the components of the ‘medicament’, combined with the condition to be treated, that must confer novelty and inventiveness. In the present case, the use of the claimed combination of trifluridine and tipiracil for treating solid cancers was known, and the Applicant’s invention lay in the triple combination.
The Commissioner thus concluded that claim 1 was not clearly directed to what the Applicant has discovered and does not comply with the definition of Swiss type claims as discussed in Pharmac. The Applicant has been directed to amend claim 1 to refer to the use of all three active substances (i.e. trifluridine, tipiracil, and irinotecan) in the manufacture of the medicament for the treatment of solid cancers.
What does it mean that all three active substance are included in the medicament? Does this limit the scope of protection to an admixture? Or could the medicament be a co-pack? Would it be an infringement to buy each active substance individually from a different manufacturer and later sell them together with instructions for use in combination?
We don’t believe there are any clear answers to these questions at this stage, and look forward to further decisions from IPONZ and the courts clarifying the interpretation of Swiss-style claims in New Zealand.