How life sciences innovators can avoid patent term extension pitfalls in Japan

Despite a significant recent judgment, uncertainties remain over the claim scope covered by PTEs in Japan, explains Toshiyasu Ishioka of Sonoda & Kobayashi

One of the world’s largest domestic healthcare markets and a major centre of pharmaceuticals R&D, Japan is a top-priority jurisdiction for protecting life sciences IP. As in other major, advanced economies, this involves seeking extensions to patent terms to compensate for lengthy regulatory approval processes.

So, to help you to navigate the country’s IP pitfalls, IAM asked Toshiyasu Ishioka to highlight the country’s major patent term extension (PTE) issues and provide his top tips for extending patent protection.

The nature of patent term extension rights in Japan

PTE is available when a regulatory approval has been obtained for a human drug, a veterinary drug, an in vitro diagnostic agent or an agricultural chemical, which is covered by the patent. The drug can be a cellular and/or tissue-based product or a gene therapy-related product, such as cultured or engineered cells. But PTE is not available when the regulatory approval is for a medical equipment or device.

Patents on active ingredients, formulations, medical/agricultural uses (medicament claims or composition for use claims), dose regimens or other modes of administration (medicament claims limited by specific modes of administration), or manufacturing methods are eligible for PTE. Patents on intermediate compounds of the active ingredients or catalysts to produce the active ingredients are not eligible.

It is possible to apply for multiple PTEs for one patent (based on different approvals) and multiple PTEs for multiple patents based on one regulatory approval. The claim scope for which the term is extended is limited by each approval independently.

The term can be extended by a maximum of five years and is calculated from the date of filing a clinical trial plan or the patent registration date, whichever is later, to the approval date. If no clinical trial was performed (e.g. the approval application was based on public knowledge), the term is calculated from the filing date of the approval application to the approval date (usually about one year). This calculation is not limited to clinical trials conducted within Japan, and the term to be extended can include the period during which a clinical trial is conducted outside Japan.

Problems and uncertainties

The IP High Court (IPHC) in Japan handed down a decision (Heisei 28 (Ne) 10046) on the claim scope covered by PTE on January 20, 2017. Prior to this decision, there were almost no court decisions regarding the claim scope. However, even this IPHC decision failed to clarify the claim scope covered by PTE. This is the most serious problem with PTE in Japan.

The IPHC Decision concluded that the scope covered by PTE is basically limited to the approved product and its approved use/indication, but also includes the scope that has substantially the same actions/effects and/or purpose as the approved product and the patent whose term has been extended. The IPHC stated that for example, if the patent concerns an active ingredient, products exhibiting substantially the same effects as the approved product and containing the same active ingredient as the approved product but also a different ingredient that belongs to conventional art will fall under “substantially the same scope” for which PTE applies.

As you can see, the claim scope covered by PTE definitely includes the approved product with the approved use, but it is difficult to define or even predict “substantially the same scope”.

Another problem relates to multiple PTEs being awarded for a single patent. This is not the subject of a legal dispute, but shows a defect in the system. If the term of a patent is extended twice based on two approvals, an earlier (first) approval relying on a longer basic clinical trial and giving a longer extension and a later (second) approval (e.g., improved regimen, formulation, additional indication) relying on an additional shorter clinical trial and giving a shorter extension, this can result in the problem of the extension based on the second approval, covering an improved formulation or additional indication, expiring much earlier than the extension based on the first approval. In other words, even if the second approval covers a better formulation, protection thereof can expire before the first approved product.

Advice for avoiding PTE pitfalls in Japan

First, I recommend being fully aware of the statutory deadline. The deadline to file a PTE application is three months from the approved date.

In addition, if the approval is expected to issue during the last six months of the original patent term (i.e. from 19 years 6 months to 20 years from the filing date of the patent application), a formality document must be filed before the last six months.

Second, as explained above, the claim scope covered by PTE is essentially limited by the approved product with the approved use. Thus, every time an additional approval (e.g. new regimen or indication) is obtained, an additional PTE application should be filed based on the additional approval.

Third, I recommend adjusting the claim format, etc. to the Japanese practice during prosecution. As mentioned above, patents on active ingredients, formulations, medical uses (medicament claims or composition for use claims), dose regimen or other modes of administration (medicaments limited by specific modes of administration), or manufacturing methods are eligible for PTE. However, Swiss-type claims and purification methods are basically not manufacturing methods and may not be eligible for PTE. The JPO is not very strict in examination of PTE applications and has allowed PTEs for Swiss-type claims or other method claims, but it would be safer to adjust the claim format.

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