2022 (Gyo-Ke) 10084 [Therapeutic Agent for Severe Heart Failure] <Honda>
更新日：12 時間前
Article information
Article type: Case note
Category: Patents
Topics: Inventive step, Motivation and teaching away
First published on this website: 2026-11-01
Display and classification checked: November 2, 2026
Originally published on Ameblo: 2025-04-24 (Japan time). Full English translation.
2022 (Gyo-Ke) 10084 [Therapeutic Agent for Severe Heart Failure] <Honda>
*It is permissible to assess obviousness by treating differences in target patients and differences in dosage and administration as separate differences.
*Although the patients were limited, the known drug had also been administered to those patients, making the invention obvious.
(Excerpts from the court's reasoning)
When considering a therapeutic drug's dosage, differences in target patients and treatment should naturally be taken into account. In identifying differences between a patented therapeutic-drug invention and a cited invention, once differences concerning target patients or treatment have been identified, there is no need to identify them again as part of a dosage difference encompassing those patients or treatment. Accordingly, the trial decision did not err in identifying only the daily dosage of tolvaptan as Difference 2, separately from Difference 1 described above. …
The patented invention differs from the invention in Exhibit Ko 2 in being specified as a therapeutic agent for severe heart failure whose oral administration is initiated in hospitalized NYHA class IV patients (Difference 1), and in specifying the daily dosage of the active ingredient as within a range of 0.371 mg/kg or less (Difference 2).
However, regarding Difference 1, at the priority date diuretics were widely used regardless of acute or chronic heart failure or its severity. Diuretics with the same mechanism of action as tolvaptan were also administered to NYHA class IV patients. Thus, there was ample motivation to use the tolvaptan of the invention in Exhibit Ko 2, effective for NYHA class I–III patients, including patients who cannot immediately be regarded as nonsevere, to treat NYHA class IV patients. No inhibiting factor is identified, and this could readily have been conceived. Further, whether the patient is hospitalized when the drug is administered can hardly be called a substantive difference. Moreover, given how tolvaptan was used at the priority date, oral administration was a matter that a person skilled in the art could appropriately adopt. Difference 2 likewise concerns a dosage substantially identical to the minimum effective dose of 30 mg once daily in the invention in Exhibit Ko 2. Setting the daily dosage within 0.371 mg/kg or less cannot be said to have critical significance, and adopting that range in light of Exhibit Ko 2 and common general technical knowledge was something that could appropriately be done. …
…Diuretics were widely used to treat fluid retention, congestion, edema and other symptoms of heart failure, regardless of whether it was acute or chronic, severe or mild-to-moderate. Furthermore, because the examples in the above argument include heart-failure treatments other than diuretics, they cannot be read as stating that diuretics should be treated differently because a patient is NYHA class IV. In addition, the trial in the patent included a mixture of NYHA class III and IV patients, and the number of deaths among class IV patients alone is not disclosed, so the effect on NYHA class IV patients is unknown.
Translator’s notes (editorial)
The introductory source uses the homophone for capacity where dosage is intended; rendered as dosage in context.
Related articles
Update history
The first-published date remains unchanged. Display maintenance, classification changes, related-article updates, and text corrections are recorded separately.
November 1, 2026: First published on this website.
November 2, 2026: Added article information, classification, topics, language navigation, related articles where the same case was confirmed, consultation guidance, and SEO. The original text and first-published date were preserved.
