[Judgment dated December 25, 2019 (2019 (Gyo-ke) No. 10006/ No. 10058) Action of revocation of trial decision

1. Point of the judgment

   The issue disputed in the case is an inventive step of a second medical use (different usage of a known substance already used in the first medical use) invention of an aqueous suspension comprising mometazone furoate.

   The patentee claimed that the invention showed an effect of “lower systemic absorption” in the second medical use, in which the systemic absorption of mometazone furoate is lower when administered intranasally as aqueous suspension, compared to oral administration. However, the effect of lower systemic absorption in the second medical use was not taken into consideration in this judgment, since the cited invention pertaining to the first medical use also uses mometazone furoate as an aqueous suspension given by intranasal administration.

   In my view, since the route of administration shall be determined depending on each of the medical uses, the effect of lower systemic absorption should be taken into consideration as an original effect of the second medical use, even though the route of administration in the first medial use of the cited invention, is the same as that of the claimed invention.

   Recently, great attention has been paid to second medical use of low molecular compounds. We should keep a close watch on the future trends to see how high the hurdle of the patentability of second medical use inventions will be set in the Japanese Court.

Section 1 Parties concerned

   Plaintiff 1: KYORIN Pharmaceutical Co., Ltd.

   Plaintiff 2: Merck Sharp and Dohme Corp. (Patentee)

   Defendant: Toko Pharmaceutical Co., Ltd.

Section 2 Claimed invention and cited invention

2-1 Claimed Invention (Patent No. 3480736)

   The claimed invention is a medicine comprising aqueous suspension of mometazone furoate, wherein the medicine is given by intranasal administration once a day for treatment of allergic or seasonal allergic rhinitis.

2-2 Cited Invention

   The cited invention is an aqueous suspension comprising mometazone furoate hydrate by intranasal administration for treatment of inflammation.

Section 3 Gist of Judgment

   The claimed invention is a second medical use invention of mometazone furoate that has an efficacy to allergic rhinitis, and its route of administration is an intranasal aqueous suspension administration. On the other hand, the cited invention is a first medical use invention of mometazone furoate that has an efficacy as an anti-inflammatory agent, and its route of administration is also an intranasal aqueous suspension administration. That is, both inventions have the common route of administration, which is an intranasal aqueous suspension administration.

   In the working examples shown in the specification of the claimed invention, blood concentration of a human was measured after being applied with mometazone furoate by various routes of administration, such as an intravenous infusion, an oral administration, an oral administration of aqueous suspension, and an intranasal administration of aqueous suspension. As a result of the measurement, none of the metabolites of the medicine was detected in the human’s blood plasma in the case of intranasal administration of aqueous suspension.

   Therefore, the patentee argued, as an effect of the claimed invention, that the systemic absorption of mometazone furoate is lower in the case of the intranasal administration of aqueous suspension compared to the case of the oral administration. However, Court denied the argument as follows, because the effect does not pertain to any of the differences between the claimed invention and the cited invention.

It can not be found that the numerical values relating to the oral solution and the oral aqueous suspension and their comparisons described in the present specification are described as effects of the claimed invention. Thus, the comparison between the oral solution or the oral aqueous suspension and (the intranasal administration of aqueous suspension) shall not be found as an effect.

Section 4 Analysis

   In a second medical use claim, there shall be a case, for example, where although its dosage and administration (route of administration) are the same as the first use, only its effects (usage) are different from the first use. In such a case, it is inappropriate to deny the effects pertaining to its route of administration in the second medical use, even though the effects are already found in the first medical use.

   In the present case, Court didn’t find the above effect as the effect of the claimed invention since the effect pertaining to the route of administration (the effect that the systemic absorption is lower if the administration is done by intranasal aqueous suspension, not by oral administration) is solely due to the selection of the administration route and is not the effect pertaining to the discovery of the new usage of the medicine (the second medical use for curing allergic rhinitis) separately from the first medical use (anti-inflammatory agent). .

   However, it is considered to be unusual in a second medical use invention to simply follow the administration route of the first medical use. It would be rather normal, for the second medical use, to select the original route of administration that would show appropriate medicinal effects, independent from the administration route in the first medical use. Thus, it seems improper not to take the effect in the second medical use relating to the selection of administration route described in the specification into consideration, even though the administration route selected in the second medical use invention is the same as that of the first medical use invention (the cited invention).

   In my point of view, it would have been possible to apply an approach of considering the effect asserted by the patentee simply as an unique effect in the second medical use for treatment of allergic rhinitis.