This article features Masaki Morishima who is a veteran patent lawyer and partner of Saegusa & Partners. He offers a detailed analysis of Japan’s Patent Prosecution Landscape, focusing on biotech and sciences.

Could you explain to our international readers the Japanese patenting process and the main regulations that support it?

In order to begin the process of Japanese patent prosecution, you can either file a national application with the Japan Patent Office directly or enter the Japanese phase of your PCT application. In either case, an examination request must be submitted to the JPO in order for the examiner to determine the patentability.

This request can be made at any time during the three-year period following the date of the filing of the patent application. If necessary, this can delay the examination process by filing it as late as possible. This approach is particularly useful for biotech startups and similar entities, who want to buy some time in order to make important decisions during the patent prosecution process (e.g. How to amend the claims, as they may need some time to finalise their product or service.

A divisional application can be filed to achieve a similar ‘wait and see’ approach. The divisional application can be used to pursue the same scope of the parent application. If there is a situation where the parent and the child are both patenting the same invention, the issue can be resolved later by amending either or both claim sets to avoid overlap. No limit is placed on the number generations that can be included in a divisional patent application. For example, on the basis of a child’s application, another divisional (for a grandchild) may be filed.

If an examiner finds that the patent application cannot be granted, an Office Action (OA) will be issued. The applicant is given the opportunity to respond – amending claims, etc., as well as making counter arguments. The examiner may still reject the application despite the applicant’s responses if he or she so chooses.

The applicant may appeal the decision of rejection if he or she wants an appeal board to review the case (which is made up of three more experienced appeal examiners than the normal examiners). The decision of the appeal board can be appealed to Japan IP High Court. When filing an appeal, applicants should also consider whether to submit a divisional patent application as a back-up measure.

According to the JPO the key reason for patent prosecution in Japan, is “early establishment and stability of patent rights.”To achieve this, the JPO accelerated the pace of examination while providing multiple measures of revocation for third-parties. Any party may file an objection within six months of the grant date, while an interested party may initiate a nullity proceeding at any time. The JPO appears to believe that these revocations challenges, particularly oppositions, which must be launched at an early stage following grant, will improve the quality and quantity of patents.

According to the JPO “early establishment and stability of patent rights” is the key reason for patent prosecution in Japan.

We tend to believe that the JPO has not been able to achieve its expectations. The grant rate is around 75% at the JPO. This is high compared to other major jurisdictions such as the USPTO and EPO. We don’t know if this is a by-product or not of the JPO’s examination acceleration in the last decade. The JPO seems to have expected that the new opposition system introduced in 2015 will improve the quality and quantity of patents. In reality, only seven out of 1,000 patents granted in 2021 were challenged. We believe that the Japanese patent system is patentee friendly, as a patent can easily be obtained and in a short time.

Is there a way to speed up the patent process?

According to official statistics from 2022, the average patent pendency period (the time between the date of the examination request and the final deposition including the grant of a new patent) was 15,2 months. It is the shortest time period of all major jurisdictions, including the USPTO and EPO. However, the period can still be shortened by making official requests. As long as you meet certain requirements, you can request an accelerated or super-accelerated exam, or enter the Patent Prosecution Highway program.

The first action pendency under an accelerated exam (the time between the date of the request for examination and the JPO sending the first OA), is approximately 2.3 months. This can be accelerated further by a super-accelerated test. The majority of patent applications submitted by applicants outside Japan will likely meet the requirements for either type of accelerated exam.

How can a biotech applicant increase the chances of their patent application being accepted?

There are still some cautions, even if the JPO’s grant rate is very high. The JPO is relatively generous in its approach to added matter when it comes to amendments. However, they are stricter in their support requirements. These data are usually experimental and can be generalised in biotech.

The JPO’s grant rate is around 75%. This is high compared to other jurisdictions.

We believe, therefore, that, if enough technical evidence is provided in the specification, it is possible to obtain a reasonable scope of protection in Japan, particularly when considering the JPO’s liberal approach towards amendments. It is because a sufficient amount of technical evidence will allow a wider scope than a cosmetic amendment which only removes the prior art, non-working embodiments etc. The JPO may allow amendments even if the filed specification does not appear to have a clear basis from a non-Japanese practitioner’s perspective.

What are the ways in which a patent attorney’s skills can be vital?

A patent attorney who is dedicated to this role can serve as a mediator to help streamline communication between the Examiner and the Applicant. They can explain the messages of the Examiner to the Applicant so that they understand him from the perspective of the practitioners in their own country or region. They can also translate the messages of the Applicant to the Examiner so that he can better understand the Applicant from the Japanese practitioner’s point of views. This requires an understanding of Japanese practice as well as the local practice in the applicant’s region or country.

What are the most common mistakes you have seen made in patent prosecution, based on your experience?

We are increasingly asked to take on cases from other firms that have been undergoing examination. This is probably to improve the chances of success in cases that seem to be stuck. We often find in these cases that the responses of the previous patent firm to the examiner’s reasons for rejection don’t seem to directly address those comments but instead stick to their theories.

We learned that it was important to know the reasons why an examiner believes that a claimed subject matter cannot be patentable. It may be easier to do this for those who are presenting cases at their local patent offices because they have a better understanding of the local practice and the language. However, it is also important for Japanese cases that they work with a competent Japanese patent attorney.

What should biotech startups keep in mind as they manage and expand their patent portfolios when it comes time to do so?

First, to minimize costs, applicants can apply for a discount on fees. This discount is applicable to both the fee for requesting an examination and for the registration of patent rights (for up to 10 years). If a biotech startup meets the requirements for a discount, two-thirds maximum of the fees above will be discounted.

Second, because the JPO is able to grant patents quickly and has a high grant rate, applicants may want to consider filing first in Japan, then submitting the Japanese granted patent for PPH examination in other countries. This will give them a geographically wider protection.

Thirdly, it is important to carefully consider the risks involved in allowing competitors to copy a biotech startup’s invention. It is difficult to argue effectively prior user rights in court.

You must address the reasons that the examiner believes the claimed subject matter to be unpatentable.

In theory, a prior-user may still be entitled to carry on the business he or she started before the date the lawsuit was filed. This is if the user had begun the business, or was preparing to start it, prior to the date the suit was filed. The hurdle is high. A prior user might prefer to apply for their own patent due to the high grant rate.

What changes in the landscape of patent prosecution in biotech IP have you seen during your years of practice?

Three areas have seen great progress: the technical effect within the context of inventive steps, support requirements, and inherent disclosure.

In recent years, the Supreme Court of Japan and other Japanese courts have developed guidance on how technical effect is evaluated in the context of a inventive step. I think that we now have a better understanding of this. This guidance is to be welcomed but it may also mean that certain patents granted according to the old standard will be revoked if the new standard is applied. It is important to carefully review these patents.

It is important to note that the JPO may take a more strict approach to the support requirement.

Inherent disclosures are situations where, for example, a technical feature of a claim is not disclosed explicitly in an earlier art document but is necessary to a material disclosed. This is a common situation in biotech. Our solution to the problem above is to reformulate the product claim into a “use-limited” product claim that states a specific use in relation to the technical feature at issue. This is because the JPO and courts are more likely to accept the novelty of a claimed subject matter if prior art documents do not mention such an application, which is most likely the case.

In Japan, the above strategy can be used, because a stated use of a product in a claim that is directed at a non-medical matter has also a restricting effect, unlike EPO’s practice.

What advice would you offer to a patent attorney with less experience in biotech patent prosecutions?

Some biotech patents are founded on cutting-edge technology, and we frequently encounter situations where an examiner doesn’t seem to understand the technology that underpins the patent application being examined. Patent attorneys with less experience will often accept an examiner’s argument without analyzing it.

Our advice to these attorneys is to trust the power of the invention and to start thinking that the invention should be something patentable. The goal is to obtain a patent. In our experience, even when it seemed impossible to get a patent granted, we were able to find a solution in the end. A mindset that begins with doubts about the patentability is much more effective than a mentality that starts by questioning the invention.


Masaki Morishima, Partner



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Kitahama Konishi Building, 7-1, Dosho-machi 1-chome, Chuo-ku, Osaka-shi, Osaka 541-0045, Japan

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Masaki Murishima has more than a decade’s experience in patent prosecution. He is a patent lawyer and the head of Saegusa & Partners’ International Client Department. He is co-head of Saegusa & Partners’ Chemical and Biotech Department and oversees the work of nearly a dozen lawyers and staff. He works with multinational companies to launch products and file patents in Japan. His experience in drafting patent applications and prosecuting them is invaluable.

Saegusa & Partners are one of Japan’s top patent firms. Saegusa & Partners, founded in 1946 in Osaka and headquartered there, boasts a team that includes experts in organic and inorganic chemistry as well as biotechnology, pharmaceuticals and cosmetics. The firm has a particular expertise in patent law issues pertaining to chemistry and biotech. Each of its previous presidents was a patent lawyer with expertise in chemistry.

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