IP basics in Life sciences
In Japan, the share of generic drug usage had traditionally been quite low. In 2005, generic share by volume was around 30% , significantly lower compared to approximately 90% in the United States and 60 to 80% in European countries [Note 1]. At that time, Japan could rightfully be described as a country dominated by originator drugs.
However, due to policies promoting generic drug use, generic volume share in Japan has been increasing steadily, reaching nearly 90% by 2025 [Note 2]. As a result, competition between originators and generics in the market has become fiercer, and patent disputes between the two have intensified.
Against this backdrop, patent strategies have evolved. So, what kinds of strategies are we talking about? In this volume, we’ll be exploring the evolving patent strategies of originator companies.
Shutting Out Gx
– Evolving Originator Patent Strategies –
Conventional Originator Patent Strategies
As introduced in Vol. 2 “What? Is the success rate of new drug development really this low?”, the R&D journey of an originator drug – from basic research to identifying candidate compounds, through preclinical testing, clinical trials, NDA and review, approval, and ultimately price listing – is both lengthy and complex.
Along this development pathway, companies typically file different types of patents, such as substance patents, process patents, formulation patents, and use patents, at strategic points in time. This is the well-established approach to maximize the product lifecycle.
Although the patent term is a maximum of 25 years including extensions, staggering filings (substance → process → formulation → use) allows companies to extend the overall period during which a product is patent protected.
This has long been the traditional patent strategy employed by originators. However, it was relatively conservative and did not really reflect a competitive stance against generics. As the share of generics increased, originator companies could no longer remain passive and began taking more proactive actions aimed at shutting out generics.
How Can Generics Be Shut Out?
As you have learned, generic drugs can apply for approval to the Ministry of Health, Labour and Welfare after the re-examination period of the originator drug has expired. They are approved and listed for reimbursement once the originator’s patents expire.
The re-examination period refers to a regulatory system under which, for a certain number of years after a new drug is approved, the pharmaceutical company collects real-world data from clinical use and re-evaluates the drug’s efficacy and safety (Re-examination System: Article 14-4 of the Pharmaceuticals and Medical Devices Act). For new drugs, this period is typically set at eight years at the time of approval and may be extended to a maximum of ten years, but it cannot be shortened.
Separately, the timing of generic entry is closely tied to the patent landscape. In practice, generics are approved and listed once the originator’s patents expire, a process shaped by the patent linkage system (Vol. 9).
Unlike the re-examination period, patent terms can be extended – up to a maximum of 25 years – and may also be challenged through invalidation trials (Vol. 7).
Taken together, these factors point to three key levers for limiting generic entry:
(1) maintaining patent protection beyond the re-examination period,
(2) leveraging patent linkage to delay generic approval , and
(3) preparing robust defenses against invalidation trials by generic companies.
How have patent strategies evolved?
Originator companies have moved beyond traditional approaches and begun implementing the following strategies corresponding to (1), (2), and (3) above in order to shut out generics. These developments represent clear evolution in the patent strategies of originators.
Strategy 1: Maximize the use of the patent term extension system
Strategy 2: Establish new use patents ahead of generic filings
Strategy 3: Increase patent rights through divisional applications
Strategy 1: Maximize the Use of the Patent Term Extension System
As introduced in Vol. 4, the pharmaceutical patent term can be extended by up to five years. Do you remember what makes the Japanese system unique compared to other countries?
In many other jurisdictions, it is common that only one patent per pharmaceutical product can be extended once. However, in Japan, multiple patents covering a single pharmaceutical product can be extended multiple times.
Accordingly, originator companies maximize the use of the patent term extension system. Whether it is the initial approval of a drug or subsequent additional approvals, they seek to extend all relevant patents. Although extension procedures involve costs, and maintaining extended patents results in significant expenses, these costs do little to deter extending patents.
Strategy 2: Establish New Use patents ahead of Generic Filings
When a generic drug is filed, the PMDA reviews its relationship to the patent information (substance and use patents) listed in the “Info-Sheet” submitted by the originator at the time of NDA (patent linkage). If the review finds that the generic product does not pose a risk of infringing the originator’s patents, the generic will be approved. Otherwise, approval will be withheld. In this context, the more patents listed in the Info-Sheet, the greater the ability to block generic approval through patent linkage.
While substance patents cannot be obtained once the pharmaceutical is publicly disclosed due to lack of novelty, use patents may still be an option. Even if the indication (e.g., epilepsy) is already known, new patents may be granted if new findings are obtained – for example, specific dosage regimens for certain symptoms or demonstrated efficacy in specific patient populations (e.g., patients with epilepsy who do not respond to benzodiazepines).
In practice, originator companies actively pursue such use patents, including them in the Info-Sheet, and/or provide information to the PMDA in order to block generic approval.
Strategy 3: Increase Patent Rights Through Divisional Applications
A divisional application refers to an application in which part of an original patent application containing two or more inventions is filed as one or more new patent applications. The original application is sometimes referred to as the “parent,” its divisional applications as “children,” and further divisions as “grandchildren.” As illustrated below, numerous divisional applications are filed to generate multiple “children,” “grandchildren,” and even further generations such as “great-grandchildren.”
The term of patents arising from divisional applications is calculated from the parent application filing date. As a result, the patent term itself does not extend indefinitely. However, what divisional filings do is enable the creation of multiple, separate patent rights from a single original application.
Generic companies seeking to invalidate originator patents must challenge each patent individually through invalidation trials, significantly increasing both time and cost.
In this way, originator companies adopt strategies that not only extend exclusivity but also raise the barriers to entry for generic companies.
Of course, these originator strategies do not go unchallenged. Generic companies are also developing sophisticated patent strategies to counter them.
In the next volume, we’ll take a closer look at the patent strategies employed by generics. Stay tuned!
[Note 1] MHLW material: “Volume Share of Generic Drugs in Various Countries”
https://www.mhlw.go.jp/file/06-Seisakujouhou-10800000-Iseikyoku/0000114903.pdf
[Note 2] Japan Generic Medicines Association: “Trends in Generic Drug Volume Share (FY2013 -FY2025, Quarterly)”
https://jga.gr.jp/assets/pdf/media/share.pdf
Author Profile
Yasuko Tanaka
President & Patent Attorney, S-Cube International Patent Office / CEO, S-Cube Corporation
Outside Director, Strategic Capital Inc.; Part-time Lecturer, Tokyo University of Agriculture and Technology Graduate School; Expert Commissioner in Intellectual Property Litigation
Previously served in the intellectual property departments of Teijin, Pfizer, and 3M Japan, with extensive experience in domestic and international IP practice, IP strategy development, contract negotiation, IP education, and project management. Founded S-Cube Corporation in April 2013 to strengthen global competitiveness of Japanese companies through IP strategy, and subsequently established S-Cube International Patent Office in August 2013 to provide seamless services including patent prosecution. Holds a B.Sc. in Biochemistry from Chiba University (1990).
