1. Decision’s Key-point

The decision is unique in Japan in which effectiveness of a patent for a pharmaceutical basic substance was disputed.

In Nippon Chemiphar Co., Ltd (Plaintiff) v. Shionogi & Co., Ltd (Patent holder, Defendant) and AstraZeneca UK Limited (Assisting Intervener for the Defendant), the IP High Court Grand Panel 2018 April 13, 2016 (Gyo-Ke) 10182, the IP High Court showed important norms for “benefit of a lawsuit” for the judgment in a trial for patent invalidation and for assessment of inventive step in the field of chemistry.

First, regarding the benefit of a lawsuit, the decision states that “Even after a patent right expired, the benefit of a lawsuit would not disappear unless there is a special reason to believe that there are no possibilities for anyone to be claimed of compensation for damage or restitution of unjust enrichment, or to be imposed of criminal punishment, for actions performed during the term of the patent right”, and thus expelled the defendant’s claim of “no benefit of the lawsuit”. Accordingly, for a judgment in a trial for patent invalidation, benefit of a lawsuit shall be affirmed in principle even after expiration of a patent right.

Next, the decision states, in regard with identifying cited inventions that are to be referred in assessing its inventive step, that “When a chemical compound is described in publications in a form of a general formula and the said general formula has a vast number of options, unless a person skilled in the art has a reason to aggressively or preferentially choose a specific technical idea pertaining to a particular option, the person skilled in the art could not have extracted the specific technical idea pertaining to the particular option from descriptions in said publications” and thus expelled the plaintiff’s claim of lack of inventive step. Consequently, after this decision, even if many chemical formulae are given as options for substituents of a general formula in a citation, there may be a case in which claiming one of the options as the cited invention shall not be allowed.

 

    2. Patent Right

Patent No. 2648897 “Pyrimidine Derivative”

[Claim 1] (the Invention 1)

A compound shown by Formula (I) or its lactone ring closure compound.

[Chemical Formula 1]

(In the formula,

R1: lower alkyl

R2: phenyl substituted by halogen;

R3: lower alkyl;

R4: calcium ion forming hydrogen or hemicalcium salt;

X: imino group substituted by alkylsulfonyl group

dotted line: whether there is a double bond or not.)

 

    3. Summary of the judgment on “benefit of the lawsuit”

(1) Argument by a party

This patent expired on May 28, 2017 before filing of this lawsuit. So the defendant claimed that there is no benefit from this lawsuit in this case.

(2) Summary of the court decision

Since a trial for patent invalidation can be claimed after expiration of the term of the said patent right (Article 123(3) of the Patent Act), it is obvious that benefit of claiming a trial for patent invalidation, or thus benefit of claiming rescindment of a judgment rejecting a patent invalidation, shall not disappear even if the term of the patent right is expired.

Under the Patent Act before the amendment according to 2014 Act No. 36, benefit of claiming rescindment of a judgment rejecting a patent invalidation would not disappear even after a patent right expired unless there is a special reason to believe that there are no possibilities for anyone to be claimed of compensation for damage or restitution of unjust enrichment, or to be imposed of criminal punishment, for actions performed during the term of the patent right.

(3) Scope of the decision

Although the decision was made based on the Patent Act before the 2014 amendment, its obiter dictum states that the similar norm shall also be applied after the amendment.

 

   4. Summary of the judgment on specifying a cited invention

(1) Argument by a party

In order to invalidate the patent in this case, the plaintiff claimed lack of inventive step based on two cited inventions. The difference between the main cited invention and the invention disclosed in the present patent (the Invention) is that the substituted X-R1 group in the Invention is an imino group substituted by a methyl group and an alkylsulfonyl group. The plaintiff claimed that the Invention lacks inventive step because the Invention could have been anticipated by combining the main cited invention with a sub-cited invention that discloses another statin compound containing the said different substituent as “-NR4R5”.

(2) Summary of the court decision

In assessing inventive step, since “the invention disclosed in the publication” should have been the base for the judgment on whether or not a person skilled in the art could have easily made the invention of the present application based on the technical level in the art at the time of the application, “the invention disclosed in the publication” must be a specific technical idea that could have been extracted from the description in the said publication. And, if a chemical compound is described in the said publication in a form of a general formula, the said general formula having a vast amount of options available, it is impossible for the person skilled in the art to extract the technical idea pertaining to the said specific option from the descriptions of the said publication unless there is a reason for one skilled in the art to aggressively or preferentially choose a specific technical idea of pertaining to a specific option,.

The number of options for R3 as “an especially preferable compound” disclosed in A2 is extremely large and, since the plaintiff does not argue over the fact that this number is at least over 20 million, it can be said that chance of choosing “-NR4R5” for R3 and “methyl” and “alkylsulfonyl” for R4 and R5, respectively, is one out of 20 million or more.

Also, although A2 discloses not only “an especially preferable compound” but also “an extremely especially preferable compound”, “-NR4R5” is not disclosed as an option for R3 in the extremely especially preferable compound.

Furthermore, although A2 discloses working examples of a compound having the same structure for X and A in the general formula (I) in A2 as the invention in A1, “-NR4R5” is not chosen for R3 in the examples.

Even if A2 discloses alkylsulfonyl group, a reason for a person skilled in the art to aggressively or preferentially choose “-NR4R5” for R3 in the general formula (I) in A2 is not found, and, with “-NR4R5” chosen, it is difficult to find a reason for the person skilled in the art to further choose “methyl” and “alkylsulfonyl” for R4 and R5.

 

    5. Practical guidelines

(1) Regarding “benefit of the lawsuit”

According to the decision, “benefit of the lawsuit” shall be denied only in a limited case in which claim for damages lapses due to expiration of 20 years of statute of limitations in Japanese Civil Law or the like. Therefore, there is little possibility that a defense claiming for “no benefit of the lawsuit” shall be accepted.

(2) Regarding Inventive Step

The decision states that it was impossible to identify a cited invention in the case that a general formula disclosed in a publication has a vast number of options. Although this decision relates to a medical invention, the scope of the decision may extend at least to the field of general chemistry. However, medical inventions differ from inventions of general chemistry in that a little difference in a substituent may lead to a failure of activation. For this reason, at least the standard to be evaluated as “a vast number of options” may differ between in the medical filed and in the general chemistry field (for example, while it may be impossible to identify a cited invention with 100 options disclosed in publications in the medical field, a cited invention can be identified in the chemistry field even if there are 1,000 options available, or etc.).

Also, although the decision was made on identification of a cited invention in assessment of inventive step, the similar approach may be valid for novelty, and thus there is a good possibility that the scope of this decision may extend to novelty assessment.

Hereinafter, when filing a trial for invalidation or a patent appeal and disputing over novelty and inventive step of a patent in the chemistry filed in Japan, it is necessary to prevent such a situation in which a cited invention would not be identified because of the norm of this decision. Therefore, if possible, one should claim as a cited invention not a compound identified from a general formula, but a compound that specifically works in working examples. However, it is uneasy if the compound in the working examples differs largely from the compound in the invention while the compound in the general formula is closer to the compound in the invention. As a safety measure, it is preferable to claim both reasons for invalidation based on the above two compounds from one publication. On the other hand, the patentee is required to acknowledge that, in addition to conventional “teaching away” and “remarkable effect”, an issue of “identification of an invention” is newly added.