[IP Newsletter] Decision by the IP High Court regarding average molecular weight and the clarity of claims requirement

We are pleased to announce the February 2017 issue of Sonderhoff & Einsel IP Newsletter.


The plaintiff, X, filed an invalidation trial against a patent held by defendant ROHTO Pharmaceutical
Co. Ltd. which claimed a violation of the clarity of claims requirement based on the lack of clarity of
the “average molecular weight” in the claims. The JPO, however, made a decision to maintain the
The plaintiff was not satisfied with the decision by the JPO and appealed to the Intellectual Property
High Court, which led to the JPO’s decision being denied.
The subject matter of the present patent was a “refreshing composition for ophthalmology”
containing chondroitin sulfate or a salt thereof which has a specific average molecular weight. The
defendant filed a patent application in 2005, and the establishment of the patent right was
registered in 2013.


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[IP Newsletter] Decision by the Grand Panel of Intellectual Property High Court (January 20, 2017) Regarding Scope of Extended Patent Right

We are pleased to announce the January 2017 issue of Sonderhoff & Einsel IP Newsletter.


The plaintiff, a Swiss pharmaceutical company called Debiopharm, requested an injunction against defendant Towa Pharmaceutical Co. Ltd. (a generic pharmaceutical drug manufacturer) and removal from the market of Towa’s alleged infringing product based on Debiopharm’s extended patent right.
The Tokyo District Court rejected the request for an injunction by the plaintiff, and the plaintiff appealed the court’s decision to the Intellectual Property High Court. The High Court affirmed the District Court’s decision that the effect of the patent right does not extend to the alleged product.
The subject matter of the dispute was “oxaliplatin,” an infusion drug used to fight colon cancer and other related cancers. The plaintiff filed a patent application in 1995 for the drug, and the production and distribution of the drug was started by a Japanese company, Yakult, in 2005. Later, more than ten companies including Towa started selling the generic drug after they had obtained approval from the Ministry of Health, Labor and Welfare. The plaintiff filed a lawsuit against Towa because the extended patent term had not expired at the time Towa began selling the product.


For details, please check the following PDF.

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Please click here for the judgment of Grand Panel Case announced on the website by the Intellectual Property High Court.

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[Law Newsletter] January 2017 Issue: 2017 Revision of Childcare and Family Care Leave Law and Implications for Employers

On January 1 of this year, amendments to Japan’s childcare and family care leave act became effective, and although the amendments are not substantial and more incremental in nature, it is important that employers implement these detailed changes into their company’s existing work rules so that the company will be in compliance with the act.  Please see article below for more details.
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“Maxacalcitol” Manufacturing Process Patent Case

“Maxacalcitol” Manufacturing Process Patent Case

Subject: equivalent infringement

This case is a groundbreaking infringement case with regard to the doctrine of equivalents (DOE) in Japan. Here, the originator of “Maxacalcitol” (plaintiff) filed a patent infringement suit against several generic manufacturers (defendants) and the decision was rendered in favor of the plaintiff by the Japanese IP High Court. The defendants were found to infringe the process patent owned by the plaintiff under (DOE).

In the pharmaceutical field, patent infringement under the DOE was established under the “ball spline bearing case” where the Supreme Court set forth five requirements to apply the DOE.[1]  Although the Japanese IP High Court has rarely applied the DOE, this case is an exception, and the IP High Court has not only applied the DOE but has also further explained its requirements 1 (non-essential part) and 5 (special circumstance).

Summary of the case

The plaintiff owns a patent for a manufacturing process of vitamin-D-derivatives, including generic name: “Maxacalcitol” (hereinafter: “the present patent”). The defendants’ end product and process is the same as that of the patented manufacturing process except that the plaintiff uses a “cis”-isomer vitamin-D-derivative as the starting material and intermediate, whereas the defendants use its geometric isomer, i.e. a “trans”-isomer of vitamin-D-derivative. The difference of the “trans”-isomer compared to the “cis”-isomer does not have any influence on the manufacturing process according to the present patent. Further, in the last step, to receive the generic (i.e., the identical) molecule, the defendants removed the initial difference of the starting material. The last step, i.e., from the “trans”-isomer into the “cis”-isomer, is an additional step compared to the patented method. The plaintiff argued that the defendants’ manufacturing process infringes the present patent under the DOE.

The main issues were, whether the first and the fifth requirements of the five requirements of the DOE specified by the Supreme Court in the “ball spline bearing case” are satisfied.


The Court focused on requirements 1 and 5 and looked at the following issues:

  1. Requirement 1 (non-essential part): Does the essential part of the invention lie in obtaining an epoxide compound from a starting material having a vitamin-D-structure and then treating the same with a reducing agent as asserted by the plaintiff, or in whether the vitamin-D-structure of the starting material and the intermediate is a “cis”-isomer or a “trans”-isomer as asserted by the defendants?
  2. Requirement 5 (special circumstances): Does the fact that solely a “cis”-isomer vitamin-D-structure is claimed fall under a special circumstance?

Decision of the IP High Court, Grand Panel

(Decision of IP High Court; March 25, 2016)

Regarding the first requirement (non-essential part) of the DOE, the court found that “the essential part of a patent invention lies in a characteristic part constituting a unique technical concept that did not exist in prior art, among the description of patented claims“, and that “since the substantial value of the patented invention must be determined in accordance with the degree of contribution compared with prior art in the relevant technical field, the essential part of a patent invention must be evaluated based on the wording of the claims and the specification, in particular based on comparison with the prior art mentioned in the specification“. Based on that maxim, the IP High Court confirmed the decision of the Tokyo District Court and came to the conclusion that, whether the vitamin-D-structure of the starting material and the intermediate is a “cis”-isomer or a “trans”-isomer is not an essential part of the present invention, and, thus, that the first requirement of the DOE is satisfied.

With respect to the fifth requirement (special circumstances), the court stated that “if a patent owner was unable to easily enforce his/her patent right of a product at issue (such as through injunctive relief) by a mere substitution of a non-essential part of a patent invention, motivation for inventions of the society will be diminished, which is against the purpose of the patent law to contribute to the development of the industry by protecting and promoting innovations as well as social justice and the principle of equity. The doctrine of equivalents is to avoid such a situation, and even if a feature that is outside the scope of patent claims could have been easily conceived at the time of the filing, said fact alone does not constitute the reason to negate the doctrine of equivalents“.


The IP High Court came to the conclusion that the fact that the applicant did not specify a “trans”-isomer of vitamin-D-structure in the claims does not fall under the “special circumstances” of the fifth requirement of the DOE, because it is not objectively and apparently acknowledgeable that the applicant of the present patent at the time of filing had or had not recognized that a “trans”-isomer of vitamin-D-structure would substitute for the starting material. An infringement under the DOE was thus affirmed.

Our comments   The decision in the “Maxacalcitol” case will likely bring clearer guidance for IP strategies when originators consider the possibility of patent infringement suits based on their process, formulation or crystal patent, etc., after the expiration of a substance patent.

[1] The “ball spline bearing case” decision specified the following requirements as the requirements for applying the doctrine of equivalents: 1) non-essential part; 2) replaceability; 3) ease of replacement; 4) ease of conception; 5) special circumstances, such as estoppel. (Decision of the Supreme Court (third petty bench) on case No. 1994(o)1083, February 24, 1998)

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New articles in our Info Center

On June 11th, 2016 Japan’s accession to the International Patent Law Treaty will take effect. Various changes in the Japanese Patent Law related to Japan joining the treaty have recently come into force, of which we are providing an overview in this article.
Further, we are covering the revised Examination Guidelines which now allow for the protection and utilization of food inventions and the revision of the employees’ invention system in Japan.

Please follow the links above or refer to the PDF available for download below. As always, please feel free to contact us if you have any questions in particular regarding the topics covered in this news update.

Sonderhoff & Einsel News Update, June 2016 available as PDF for download.

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Sonderhoff & Einsel News Update, December 2015

Please find below a news update of our IP and Law practice groups. In this issue, we are covering a recent Supreme Court decision regarding the extension of patent terms for pharmaceutical products and the potential impact of changes to the Worker’s Dispatch Law on companies.

Please feel free to contact us if you have any questions with regards to the topics covered in this news update.

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