Patent Applicant’s Perseverance Pays Off

In Taiho Pharmaceutical Co Ltd [2022] NZIPOPAT 1 multiple grounds for rejection maintained by the examiner were found to either have no basis or were upheld with the applicant being given the opportunity to make suitable amendments.

The application in question is a divisional of a PCT national phase entry that claims priority from a Japanese application, with a priority filing date of 27th March 2013. The New Zealand claims are in Swiss-style format, whereas the national or regional phase entries in other jurisdictions that have subsequently been granted use different claim formats. The New Zealand application in question has 8 claims, with claim 1, as follows, being the only independent claim:

1. 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.

There were several outstanding objections by the examiner. Namely:

Section 40/Regulation 58/Section 33(5) – whether support for amendment in priority document
Section 39(2)(b) — whether claims are clear
Section 14(b)(i) – whether invention claimed lacks novelty
Section 14(b)(ii) – whether invention claimed involves an inventive step
Section 14(a) – whether double patenting

Claim Support:
The Assistant Commissioner rejected the examiner’s lack of support objection to claim 1 after finding that the upper range value of 130 mg/m2/day was a slight rounding up of dosages disclosed in the priority specification.

Clarity:
The examiner’s clarity objection to claim 1 concerned the absence from the claim preamble of one of the active ingredients – namely irinotecan hydrochloride hydrate. While the inventors discovered that the use of the three named active ingredients in the manufacture of a medicament is beneficial for the treatment of solid cancers, only two of those active ingredients are mentioned in the claim preamble. The Assistant Commissioner upheld that objection finding that the claim does not comply with the acceptable format of a Swiss-style claim, and ordered that the claim be amended so as to be in an acceptable claim format.

The examiner also made a clarity objection to claim 7 on account of it being dependent upon claim 6 while containing the phrase “the administration schedule” which only has antecedence in claim 5. Claim 7 is as follows:

7. The use according to claim 6 wherein the patient has received irinotecan hydrochloride hydrate within one cycle of the administration schedule.

While claim 6 can be dependent upon claim 5 it can also be dependent upon any one of claims 1-4. Consequently, when claim 6 is dependent upon one of claims 1-4 while not also being dependent upon claim 5, then claim 7 has no antecedence for the phrase “the administration schedule”. The Assistant Commissioner also upheld this clarity objection and allowed the applicant the opportunity to amend the claims either such that claim 7 is dependent on claim 6 when dependent on claim 5, or making claim 6 only dependent on claim 5.

Novelty:
The Assistant Commissioner rejected the examiner’s novelty objections, finding that neither of the prior art documents ‘planted the flag’ as they did not disclose the use of irinotecan hydrochloride hydrate with the other two active ingredients and one of the documents disclosed a different chemical structure for tipiracil hydrochloride.

Obviousness:
In addition to the above differences the lack of inventive step objection also took into account further differences. The first document (Temmink) gave the best chance of establishing obviousness, yet used higher dosages of trifluridine and tipiracil hydrochloride and even taught away from using a lower dosage. While the higher dosage ranges in Temmink would be within the common general knowledge of a person skilled in the art, the Assistant Commissioner found that it would not be obvious to a person skilled in the art to use the dosage range given for those active ingredients in claim 1.

While Temmink did not disclose the use of irinotecan hydrochloride hydrate with the other active ingredients mentioned therein, it did indicate that combining irinotecan hydrochloride hydrate with the disclosed active ingredients could be worth trying. The examiner considered that to provide a realistic expectation of success for the combination of the three active ingredients claimed in Taiho’s application. However, the Assistant Commissioner rejected that contention, holding that Temmink did no more than speculate on the combination as it contained no studies of the effect of using the combination. At best it provided a motivation to try the combination, but even then the Assistant Commissioner considered that establishing the dosages would require some degree of inventiveness, especially in light of dosages being used that are lower than what would be common general knowledge for the person skilled in the art. Consequently the obviousness ground was rejected.

Double Patenting:
The examiner had raised a double patenting objection in relation to a granted patent also in the name of Taiho having the same priority and international filing dates and having very similar claims. Despite the similarities the Assistant Commissioner noted that the regulation 82 prohibition on double patenting does not apply as the patents are not linked in the parent – divisional relationship required by regulation 82. Nonetheless, the Assistant Commissioner noted from the precedential UK case Dreyfus’ Applications (1927) 44 RPC 291 that where an applicant has two applications having the same priority date directed towards the same invention only one of the applications will be allowed to proceed to grant. However, after comparing the claims, the Assistant Commissioner concluded that there is no double patenting as neither the patent nor the application claims matter falling wholly within the scope of the other. In particular, claim 1 of the granted patent includes an administration schedule and has a higher dosage range for irinotecan hydrochloride hydrate that does not fully contain the range for that active ingredient in the application.

Author: Quinn Miller

//piperpat.com/news/article/patent-applicants-perseverance-pays-off