Summary of the case
Shionogi is the owner of a patent entitled Pyrimidine
Derivatives (JP2648897). X filed a request for a trial for
invalidation of the patent. Nippon Chemiphar intervened in the
trial as a plaintiff, and AstraZeneca UK intervened in the
trial in order to support the defendant.
The scope of the claim 1 of the patent after the correction
(invention 1) is described as follows:
Claim 1 (invention 1)
A compound represented by the formula (I):
R1 is lower alkyl; R2 is phenyl substituted by halogen; R3
is lower alkyl; R4 is calcium ion forming hydrogen or
hemi-calcium salt; X is imino group substituted by
alkylsulfonyl group; and the dotted line represents the
presence or absence of a double bond, or the corresponding
The Japan Patent Office (JPO) dismissed Nippon Chemiphar's
request. Nippon Chemiphar appealed to the IP High Court seeking
rescission of the JPO's decision.
Since the patent right lapsed during the litigation,
Shionogi argued that Nippon Chemiphar lacked any interest in
filing an action. It asserted that the case should be dismissed
because Nippon Chemiphar did not practise the patent right
during the patent term, and Shionogi did not have the right to
claim compensation for damages.
Judgment of April 13 2018, the Grand Panel of IP High
The Grand Panel of the IP High Court (Presiding Judge
Shimizu) dismissed Nippon Chemiphar's claim holding as
1) Interest in filing an action
An interest in filing an action to seek rescission of the
JPO decision dismissing the request for trial for patent
invalidation still exists even after the lapse of the patent
right. This is the case unless there is a special circumstance;
there must be no possibility that anyone is subject to a claim
for compensation of damages, a claim for return of unjust
enrichment, or a criminal penalty regarding conduct during the
patent term. Here, no special circumstance was found.
2) Inventive step
When a cited invention is a prior art disclosed in the
publications and the compounds of the invention are described
by a general formula which has an enormous number of choices,
unless circumstances exist to positively or preferably
ascertain the technical idea regarding a certain choice, the
concrete technical idea regarding the certain choice cannot be
extracted and it cannot be a cited invention.
The cited invention 1 is specified as a compound whose
substituent M represents sodium.
The common features and differences between invention 1 and
the cited invention 1 are detailed below.
The common features
R1 is lower alkyl; R2 is phenyl substituted by halogen; R3
is lower alkyl; and the dotted line represents the presence or
absence of a double bond, or the corresponding ring-closed
(1i) X in invention 1 represents the imino
group substituted by alkylsulfonyl group, whereas X of the
cited invention 1 represents the imino group substituted by
(1ii) R4 of invention 1 represents the
calcium ion forming hydrogen or hemi-calcium salt, whereas R4
of the cited invention 1 represents the sodium ion forming
Regarding the difference (1i), the plaintiffs argued that
skilled persons can easily arrive at the constitutions in
invention 1 by combining the cited invention 1 with the cited
invention 2, specifically by substituting one of the two methyl
groups (-CH3) included in dimethylamino group (-N(CH3)2)
located in the second position of pyrimidine group of a
compound of the cited invention 1 with alkylsulfonyl group
(-SO2R' (R' represents alkyl group) ) of cited invention 2.
The cited reference 2 (JPA1989-261377) discloses the
A substituted pyrimidine represented by formula (1):
R1 is alkyl; R2 is aryl; R3 is alkyl wherein the said
substituent is -NR4R5 wherein R4 and R5 are identical or
differential and are alkyl or alkylsulfonyl; X is -CH=CH-; and
A is group represented by the formula below.
R6 is hydrogen and R7 is a cation.
The cited reference 2 discloses -NR4R5 as a choice for the
substituent R3 as "a particularly preferred compound" among the
general formula (I), and also discloses methyl group and
alkylsulfonyl group as the choice for R4 and R5.
However, the choices for R3 as "particularly preferred
compounds" described in the cited reference 2 are extremely
large in number. There are at least more than twenty million
choices. Thus, selecting methyl group and alkylsulfonyl group
as R4 and R5 of -NR4R5 as R3 is one of more than twenty million
In addition, the cited reference 2 discloses not only
"particularly preferred compounds" but also "particularly
extremely preferred compounds". However, the latter does not
disclose -NR4R5 as a choice for R3.
Furthermore, -NR4R5 is not disclosed as the choice for R3 in
the examples of compounds which X and A of the general formula
(I) of the cited invention 2 represent as the same
constitutions as in the cited invention 1.
It is impossible to ascertain from the cited reference 2 how
skilled persons should positively or preferentially select
-NR4R5 as R3 of the general formula (I) of the cited invention
2. Thus, it is difficult to assert that skilled persons would
select methyl group and alkylsulfonyl group as R4 and R5 after
Under the Japanese patent linkage system for product patents
that the Ministry of Health Labour and Welfare will not approve
unless the product patent is invalidated by the JPO, factors
seem to exist which lean towards denying the interest in filing
an action under the facts of this case. However, the court held
the interest in filing an action will not be lost even after
the lapse of the patent right unless there is a special
circumstance. Legally, the door remains open to file a
litigation rescinding the trial decision even after the lapse
of the patent right. However, as the generic drug manufacturer
can receive approval after the lapse of the patent right even
without filing such a lawsuit, this lawsuit makes no sense from
a business perspective. As a result, similar lawsuits will not
increase in the future.
There will be a dispute in the future about what "enormous
number" means. As the court pointed out "at least more than
twenty million" in this case, this number will be a good
indicator. Whether a certain choice is described as examples is
a key factor when deciding whether circumstances exist to
positively or preferably establish a technical idea regarding a
certain choice, if the cited invention is a patent.
This judgment became final and binding without being
ABE & Partners
Matsushita IMP Building
1-3-7, Shiromi, Chuo-ku, Osaka, 540-0001, Japan
Tel: +81 6 6949 1496
Fax: +81 6 6949 1487