Case in which the defendants’ products have been judged not to infringe a medicinal use invention characterized by a dose

TERACHI, Takumi
Japan Patent Information Committee

• Heisei 26 (2014) (Wa) No. 25013, A case seeking an injunction against infringement of a patent right, etc. –
• Heisei 28 (2016) (Ne) No. 10023, A case seeing an injunction against infringement of a patent right, etc. –

In the subject case, it was contested whether the manufacture and sales of a remedy for Meniere’s disease, the standard dose of which is disclosed to be 1.5 to 2.0 mL/kg body weight per day and the package insert of which states “may be increased or decreased as appropriate depending on the symptom,” violates a patent right pertaining to a remedy for Meniere’s disease characterized in that the oral dose of isosorbitol is from 0.15 to 0.75 g/kg body weight of an adult per day. In the court of first instance, the patented invention was restrictively interpreted based on the disclosures of the specification of the subject patent, and it was concluded that the above-mentioned sales and manufacture are non-infringing on the grounds that in the case where the dose is reduced at a physician’s discretion depending on the characteristics of an individual patient or changes in his or her pathological conditions, the reduced dose does not belong to the technical scope of the subject invention even if it corresponds to the dose disclosed in the patented invention. This conclusion was maintained by the IP High Court without referring to how the technical scope of the patented invention should be interpreted, on the grounds that the working by the appellees does not fall under the working of a use invention, i.e. the subject patented invention.

There are few examples of judgment made about the technical scope of a medicinal use invention, especially one that is characterized by a dose, so the subject case should be referenced when interpreting the technical scope of a medicinal use invention.

(1) Subject

The subject patent is Patent No. 4778108 (Title of Invention: Remedy for Meniere’s disease; Priority Date: March 21, 2008; Registration Date: July 8, 2011), and Claim 1 reads as follows (hereinafter the underlined part is referred to as Constitutional Requirement A).

[Claim 1]
A remedy for Meniere’s disease containing isosorbitol, characterized in that the remedy is used such that 0.15 to 0.75 g/kg body weight of isosorbitol is administered orally to an adult per day (provided that the case where a polysaccharide is concomitantly administered in an amount of 1 to 30% by mass relative to the isosorbitol via the oral route is excluded).

(2) Defendants’ (Appellees’) Products

The defendants have manufactured and sold the defendants’ product 1 since June 1, 1968, the defendants’ product 2 since July 1, 2008, and the defendants’ product 3 since March 19, 2010, as pharmaceutics having a function as an agent for ameliorating Meniere’s disease (i.e. a remedy for Meniere’s disease). The disclosure about the dosage and administration for Meniere’s disease provided in the package insert and interview form of the defendants’ products reads as follows: “the standard dose is 1.5 to 2.0 mL/kg body weight per day, and the daily dose of 90 to 120 mL for a normal adult is orally administered in three divided portions, i.e., after each meal. It may be increased or decreased as appropriate depending on the symptom.”

(3) Judgment by the court of first instance (the Tokyo District Court)

The points contested in the court of first instance were (i) the fulfillment by the defendants’ products of Constitutional Requirement A (note that the defendants did not dispute the fulfillment of the other constitutional requirements), (ii) the presence or absence of grounds for invalidation of the subject patent and (iii) the amount of damage. In the subject case, judgment has been made only about (i).

The judgment rendered in the court of first instance cites the following description in the specification:
The dose of the pharmaceutical agent must be adjusted as appropriate depending on differences among individuals, severity of symptoms, etc., and it is frequently encountered in clinical settings that even a reduced dose provides a comparable or more than comparable efficacy. However, the significance of reducing the dose in the present invention is different from such a practice which is commonly called “a physician’s consideration in prescription.” (paragraph [0032])

In the judgment, the Court states to the following effect: according to the disclosures of the subject specification, the doses of conventional isosorbitol formulations are excessive, thereby causing various problems, but the subject invention solved this difficulty by reducing the dose to the range of 0.15 to 0.75 g/kg body weight as recited in Constitutional Requirement A; it then follows that the remedy of the subject invention is limited to ones that are used in such a way that isosorbitol is administered in amounts smaller than in the conventional case, excluding any usage in which isosorbitol is administered in amounts beyond the range recited in Constitutional Requirement A. In regard to the technical scope of the patented invention, the Court held that a remedy to be used in such a way that isosorbitol is administered in amounts beyond the above-noted range should be regarded as not belonging to the technical scope of the subject invention, even if it could be used in such a way that the amount of isosorbitol is as  recited in Constitutional Requirement A in the case where the dose is reduced at a physician’s discretion, i.e. as “a physician’s consideration in prescription,” depending on the characteristics of an individual patient or changes in his or her pathological conditions.

Based on this observation, the Court concluded as follows concerning the statement “may be increased or decreased as appropriate depending on the symptom” provided in the package insert, etc.: the above-noted phrase of “increased or decreased as appropriate” is interpreted to mean that the dose is increased or decreased at a physician’s discretion in view of the symptom of the patient at the start of administration or its subsequent changes, so even if there exist cases in which, as a result of such appropriate increase or reduction, the dose of isosorbitol comes to encompassed by the range specified in Constitutional Requirement A, this cannot be relied upon to say that the defendants’ products belong to the technical scope of the subject invention.

(4) Judgment by the court of second instance (the IP High Court)

In the second instance, the Court defined a use invention and its working as follows: use inventions are characterized in that an unknown property of a known substance has been found and that a novel use having a marked effect has been created based on said property, so it is reasonable to consider that the “working,” as stipulated in Article 2, Par. 3 of the patent law, in the case of a use invention is limited to the acts of manufacturing, using, assigning, etc. of the known substance in order to apply it for the novel use.”

In regard to the subject patented invention, the Court made the following remark: with a view to solving the problem of conventional remedies for Meniere’s disease, i.e. long time is required until the onset of their action, the subject invention reduces the daily dose of the known substance isosorbitol from the conventional range of “1.05 to 1.4 g/kg body weight” to the range of “0.15 to 0.75 g/kg body weight” recited in Constitutional Requirement A, thereby providing a remedy for Meniere’s disease that not only allows rapid onset of its action such as by preventing the occurrence of plasma AVP but which is also suitable for long-term administration.” And the Court held as follows: “in regard to the dosage and administration described in the package insert and interview form of the defendants’ products, the standard dosage is 1.5 to 2.0 mL/kg body weight per day which is even greater, rather than smaller, than the doses of conventional isosorbitol formulations that are referred to in the subject specification, and, hence, it is recognized that said standard dosage obviously exceeds the above-noted use which is stipulated by Constitutional Requirement A;” and “there is no other evidence sufficient for one to recognize that the manufacture and sales of the defendants’ products were done in order to apply them for the above-noted use;” based on these holdings, the Court concluded that “the appeal made by the appellant lacks grounds, and the original decision which dismissed said appeal by the appellant is reasonable.”