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Taiho 2 – Second medical use claims for combination treatments (again)
A number of months ago a colleague referred me to the decision of the Assistant Commissioner of Patents in Taiho Pharmaceutical Co., Ltd. [2022] NZIPOPAT 1 (25 January 2022) (Taiho 2) and asked me what I thought, given my previous comments here and here in relation to claims to combination treatment. At the time it felt like New Zealand had regressed to the conversations of the early 2000’s about second medical use claims that the rest of the world has long since moved on from. However, with further reflection , matters may not be quite as dire as I first thought they could be.
On its face the Taiho 2 decision appears to consider that a Swiss-type claim directed to the use of just one active ingredient in the manufacture of a medicament, but purposively limited to a combination treatment is not acceptable. Instead it appears to require that a claim where the invention lies in a combination treatment must be phrased so as to require the use of both active ingredients in the manufacture of the medicament, see for example at paragraph 57 in particular:
To place the application in order for acceptance, the applicant must amend claim 1 to direct this to the use of all active substances in the manufacture of the medicament for the treatment of solid cancers. [emphasis added]
In my article here I discuss why requiring a Swiss-type claim to be phrased in this way is undesirable and could result in limited or no protection for certain combination type treatments.
However, the actual claim presented in Taiho 2 reads:
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]
In my opinion, it is arguable that this claim is not purposively limited to the combination treatment. Firstly the term “adapted” implies a physical adaptation of the medicament, rather than a purpose. Secondly, as noted in Pharmaceutical Management Agency Ltd v Commissioner of Patents [1999] NZCA 330 (Pharmac) e.g. at [65], it is the purpose for which the medicament is made which is limiting in a Swiss-type claim. In other words any purposive limitation needs to be directed to the purpose of the manufacture, not to the medicament itself.
It follows that, as a result of the wording of the above claim, the Assistant Commissioner in Taiho 2 was not called on to decide whether a combination treatment could be protected by a properly worded purposive limitation. While the Assistant Commissioner proposed an alternative wording in his decision (as in paragraph 57 above), this does not mean that other amendments would not have also been suitable. Indeed this is one of the downsides of the current system of examination hearings whereby discussion of possible amendments is severely curtailed, especially in cases where the hearing is taken on the papers only.
It is true that the approach above is at odds with the specific language allowed in the claims of some the earlier cases for example in Merck & Co. Inc. v Arrow Pharmaceuticals (NZ) Limited [2006] NZIPOPAT 3 (31 January 2006) (used the linking phrase ‘adapted for’), and Genentech Inc and Washington University [2007] NZIPOPAT 1 (23 January 2007) (used the linking phrase ‘formulated for’). It is also add odds with guidance that has previously been provided by IPONZ in examination reports. On the other hand the approach is arguably more consistent with the Court of Appeal’s decision in Pharmac, as discussed above; allows for equivalent protection as would be allowed by a method type claim (as Pharmac held was necessary under the TRIPS Agreement (discussed further in my article here); and does not create inconsistencies with other types of previously allowed second medical use claims such as where the novelty lies in the patient group (e.g. Astrazeneca AB [2007] NZIPOPAT 23 (3 September 2007)) or dosage regime which cannot be expressed as a limitation on the manufacture itself. Furthermore, the approach is consistent with that taken in Europe to second medical use claims to combinations, notwithstanding the fact they are expressed in “Compound-for-use” type claims since the EPC2000 amendments were introduced.
So where to now? The Assistant Commissioner’s decision in Taiho 2 is not binding, either on the examination team or any other Court and it is likely to be some time before we see a binding decision of the High Court (or above). In the meantime, the examination team needs to decide how persuasive Taiho 2 is. The above provides a potential approach by which Taiho 2 could be understood as persuasive to an extent, but still allowing purpose limited Swiss-type claims. Alternatively, the examination team may consider that Taiho 2 is incorrect in its construction of terms such as ‘adapted for’ and choose to continue to consider such phrases as limiting, consistent with the earlier Assistant Commissioners’ decisions noted above. As evident from the above, in my opinion treating the Assistant Commissioner’s comment at paragraph 57 of Taiho 2 as binding should be avoided.
In some good news for New Zealand patent applicants, a recent search of IPONZ applications has shown a number of cases which have been accepted for combination treatments where the claim is not expressed as the use of both active ingredients in the manufacture of a medicament. Thus it does appear as though the examination team is allowing some form of purposive limitation. However, the exact approach the examination team is taking will not be known until (if) they issue guidelines on the subject.
David Nowak - June 2023
