Overview of the Patent Term Extension in Japan｜IP Laws & Practices

6. Examination of the patent term extension application

6-1. The regulatory approval must be the first approval received with respect to the Product (active ingredient) and Use (indication/effect).(1) Subsequent approvals for the same active ingredient and indication/effect that only differ in dosage form, administration etc., cannot serve as a basis for an additional extension.
(2) Subsequent approvals for the same active ingredient differing only in the indication/effect may serve as a basis for an additional extension*.
(3) Subsequent approvals for the different active ingredient covered by the broadest claims may serve as a basis for an additional extension*.
* Scope of protection of the patent right during the extended patent term is limited as discussed in Section 7.

NOTE: The term of patent may be extended only if the regulatory approval on which the application for patent term extension relies is the first approval received with respect to the Product (active ingredient) and Use (indication/effect).
In other words, subsequent approvals for the same active ingredient and indication/effect that only differ in dosage form, administration etc., cannot serve as a basis for an additional extension. However, an important aspect of the patent term extension system in Japan is that a patent may be extended based on a subsequent approval if the approval is directed to a different indication from that of the previous approval.
Similarly, a patent may be extended based on a subsequent approval directed to a different active ingredient (excluding different salt) from that of the previous approval insofar as the different active ingredient is covered by the claims of the patent.
As can be seen, while a patent may be extended more than once based on different regulatory approvals, the scope of protection provided by the extended patent term is restricted as explained in Section 7 below.

Examples

NOTE: The above shows the Examples.

In case 1, the patent claiming compounds A, B and C may be extended based on the first, second and third regulatory approvals because these approvals are directed to a different active ingredient and/or indication.
In case 2, the patent claims a use of Compounds A, B and C for viral infections treatment. In this case, the patent cannot be extended based on the second approval because the indication specified in the approval is cancer treatment and therefore irrelevant to the claimed use in the patent. However, the patent may be extended based on the first and third approvals because of the difference in the active ingredient between them.
In case 3, the patent may not be extended based on the first and third approvals in view of the difference between the specified use in the patent and indications in the approvals. In case 4, the patent may only be extended based on the third approval because the patent does not claim Compound A.
In this connection, the relationship between the indications of anti-viral and anti-HIV should be considered. Under the Japanese Law and Rules, if the first approval is directed to the anti-viral (generic concept) and the second approval is directed to the anti-HIV (species), the patent may not be extended based on the second approval.
In contrast, if the first approval is directed to the anti-HIV (species) and the second approval is directed to the anti-viral (generic), the patent term may be extended based on the second approval because the second one includes other indications (viral infections) except for HIV infections and therefore the patent term may be extended with respect to other viral infections except for HIV.

6-2. More than one patent may be extended based on a single regulatory approval.Where Product (compound) patent, Use patent and Process patent are involved, each patent may be extended based upon a single regulatory approval.

NOTE: Another important aspect of the Patent Term Extension system in Japan is that more than one patent may be extended based on a single regulatory approval.
Specifically, if there are two or more patents involved, e.g. Product (compound) patent, Use patent and Process patent, each patent may be extended based upon a single regulatory approval insofar as these patents cover the active ingredient approved by the regulatory authority.

Examples

Case: Regulatory approval for compound A as active ingredient in viral infections treatment (indication)

NOTE: The above examples show that Product, Use and Process patents may be extended based on a single regulatory approval insofar as these patents cover the active ingredient (and indication, if relevant) approved by the regulatory authority.
In relation to the process patent, a patent just claiming an intermediate may not be extended by any regulatory approval because the intermediate, even if solely used in the preparation of the active ingredient, is not a direct subject of the regulatory approval. Adequate coverage needs to be provided by process claims.