6. Second Use of a Known Pharmaceutical Composition

Second Use of a Known Pharmaceutical Composition

Second use of a known pharmaceutical composition is patentable in Japan.

The novelty of a pharmaceutical invention is judged from the two viewpoints; one is the compound contained in the composition, and the other is the pharmaceutical use (e.g., The Tokyo High Court Judgment of April 25, 2001 (Heisei 10(Gyo Ke)401) etc.). Therefore, even if there is no difference in composition from a known pharmaceutical composition and if the second pharmaceutical use is clearly different from the first pharmaceutical use, the pharmaceutical composition is patentable for the second use. However, if the second use is the species of the first use, for example, then the second use would not be distinguishable from the first use. In addition, if the second use can be derived from the first use (asthma treating composition vs. a bronchio-dilatation composition), then the novelty of the second invention would be denied.

Patent term extension

Patent term extension

The extension of patent term is available for human pharmaceuticals, as well as animal drugs and agricultural chemicals. .

Because the extension is a provision to compensate for the patent term that has been eroded due to the delay of a regulatory approval, it is allowed in only case that a patent fulfills all the following requirements i)-iii):

  1. a regulatory approval (=allowance) from the Japanese Health, LabourandWelfareMinistry was necessary to work the patent, therefore the request of investigation was asked before or after the grant, (please refer to the illustration below: types 1 and 2)
  2. the regulatory approval (=allowance) was received from the Japanese Health, LabourandWelfareMinistry after the grant, and
  • due to the delay of the above approval, the patent could not be carried out (=patented products could not be produced or sold).

* type 0 : A request of investigation is asked before the grant and the allowance was also received before the grant.  In this case no extension is available.

type 1 : A request of investigation is asked before the grant and the allowance was received thereafter.  The extension term is calculated from the grant.

type 2 : A request of investigation is asked after the grant and afterward the allowance was received.  The extension term is calculated from the request of investigation.


extension duration

If a patent fulfills all the requirements above, the patent can be extended for 5(five) years at the maximum.  The extension duration corresponds with the term that the patented products could not have been sold because of the absence of a regulatory approval.


request for extension

If your patent(s) meet(s) the requirements, you may request for the extension of patent duration by submitting evidence which shows the reception of a regulatory approval from the Japanese Health, Labour and Welfare Ministry.



Please note that the extension of patent duration is strictly limited to the case above, therefore the other reasons, such as a delay of the examination inside the JPO will never be considered.

Medical product

  • 3. Enablement Requirement for Medicine

    (See details in JPAA homepage)

According to the Examination Guideline, normally one or more representative embodiments or working examples are necessary which enable a person skilled in the art to work the invention, except the case where a person skilled in the art can manufacture the compounds etc. and can use the compounds etc. for medicinal use, in the light of common general technical knowledge as of the filing. As for working examples supporting the medicinal use, a description of the result of the pharmacological test is usually required.
In order to confirm the pharmacological effect of compounds etc. of the claimed medicinal invention, all of the followings should be made sufficiently clear, in principle; (i) which compounds etc. are (ii) applied to what sort of the pharmacological test system, (iii) what sort of result is obtained, and (iv) what sort of relationship the pharmacological test system has with the medicinal use of the claimed medicinal invention. It should be noted that the result of the pharmacological test should be described with numerical data as a general rule, but when the result cannot be described with the numerical data due to the nature of the pharmacological test system, an objective description equivalent to the numerical data for example, a description of the objective observation result by a medical doctor may be accepted. Furthermore, a clinical test, an animal experiment, and in-vitro test are employed as the pharmacological test system.

Pharmacological Data
If the specification includes an example which exactly describes how to test the claimed chemical composition, can the data associated with the example later be added, if it is proven that the example is actual, rather than paper or prophetic?

The written requirement (support and enablement) concerning the pharmaceutical invention is very strict in recent practice. If the pharmacological efficacy data of the pharmaceutical composition of the example (or the description which is considered equivalent to the pharmacological efficacy data) were not disclosed in the specification at the filing date of the patent application, it is almost impossible to obtain a patent for the pharmaceutical composition. The addition of the data to the specification after the filing date of the present application is considered as new matter. “Paper or prophetic examples are not considered as the working examples.

Physical-Chemical Data
What physical-chemical data are required in Japanese applications to support an invention of a composition which is a mixture of known ingredients?

The physical-chemical data should be usually required in the specification for an invention of a composition. The chemical field is the technical field where the effect of a composition cannot be readily expected based on the components constituting the composition. A composition invention is usually invented for providing a new and useful composition for some intended purpose. Such usefulness is usually proved by the physical-chemical property of the composition relating to such intended purpose. The kind of the physical-chemical property of the composition should vary depending on the kind of the composition. For example, please assume that an adhesive composition has been invented, which provides a stronger adhesive property than the conventional adhesive composition. In order to confirm that the claimed adhesive composition is indeed useful as an adhesive composition, it is natural that the specification should contain physical-chemical data based on which the adhesive strength of the claimed invention can be evaluated.

It is usually necessary for supporting the utility of an invention of a chemical compound. Physical data or test data are useful for proving that the compound was actually prepared and for proving that the compound would be useful for the intended purpose (such as the use of an effective component for a pharmaceutical composition).

As stated above, the chemical field is the technical field where the effect of a composition cannot be readily expected based on the components constituting the composition. It is usually impossible to expect the property or usefulness of the compound. Therefore, test data concerning the herbicidal effect should be usually necessary for proving an invention of a herbicidal composition.

The disclosure of the specification has to enable one skilled in the art to practice the claimed invention. The chemical field is the technical field where the effect of a compound cannot be readily expected from its chemical structure or chemical name. Further, the support requirement is recently strictly evaluated. The support requirement is to evaluate how broadly the working example justifies or generalizes the scope of the claimed invention. Therefore, it should be necessary to provide as many examples as possible at the filing date of the application. Generally, of course, at least one representative working example is required to support the chemical compound. If the chemical compound claimed is defined by the general formula covering a generic concept of a compound, which can broadly cover various distinct types of chemical structures from each other (such as an aliphatic group and aromatic group), it should be reasonably necessary to provide working examples for each one of the distinct chemical groups.

Divisionbal Application


*         Applicant can amendment (or file divisional application) freely at any time before 1st official action is issued.

However, after the 1st official action is issued, applicant can file divisional application(s) only when amendment is allowed (Article 44) in the present Patent Law (effective after 1994).  Therefore, a chance of this amendment (= chance of divisional application) is limited substantially following two times (a) and (b) after the substantial examination started *:

(a)        at the response to the official action, and

(b)        at the filing of Appeal,


There is no chance of filing a divisional application if the case is granted in Appeal procedure without any official action.  Therefore, in case of a critically important case or invention, it should be considered to file a divisional application at the time of Appeal to keep the case or to keep a possibility of further amendment.



(1)       Post-grant opposition

–           The opposition can be filed against a granted patent right (“post-grant opposition”).

–           Time limit of filing of the opposition is six (6) months from the publication date of the patent gazette.

–           Any person can be the opponent but a name of opponent must be described (the opponent can be “dummy”).

(2)       Flow of the opposition

Attached herewith please find a brief flow chart of the opposition procedure.

–           Patent Proprietor can file “Argument” and/or “Request for Correction”.

–           Opponent has a chance to argue against the Patent Proprietor’s Argument and/or Request for Correction filed.

–           Final Decision of Opposition (Revocation or Maintenance of a patent right) is issued when decision is matured.

(3)       Correction

* (In the opposition procedure, a term of “Amendment” is not used but wording “Request for Correction” is used)

Correction is limited to following four purposes (a to d) only:

a          to narrow claim ranges

b          to correct errors in typing and translation

c          to correct unclear description

d          to correct dependency in claims

Corrected claims must satisfy following requirements also:

i           new matters can’t be added.

ii          correction should neither changes nor enlarges the scope of invention

iii         corrected claims must be patentable claims (novelty, inventive step)


(4)       Appeal for Invalidation or Opposition

–           “Appeal for Invalidation” can be filed independently from the “Opposition”.

There are several differences between “Appeal for Invalidation” and “Opposition”

Appeal for Invalidation

no time limit

limited to interested parties

examined by oral hearing



|time limit of 6 months from publication

anyone can file

no oral hearing (paper examination only)

–           When “Appeal for Invalidation” and “opposition” are filed at the same time, the “Appeal for Invalidation” takes precedence.

A detail of the new opposition system is explained in following web page of JPO:



Flow chart of the opposition procedure