2017 <Special News Flash 2>｜News Letter

Supreme Court Affirms Grand Panel’s Decision of IPHC Finding Infringement of Patent relating to Chemical Process under Doctrine of Equivalents (DOE)

DKSH Japan Co., Ltd., Iwaki Seiyaku Co., Ltd., Takata Pharmaceutical Co., Ltd. and Pola Pharma Inc. v. Chugai Pharmaceutical Co., Ltd., Case No. 2016 (Ju) 1242 (Decisions rendered on March 24, 2017)

The Supreme Court affirmed the decision of the Grand Panel¹⁾ of the Intellectual Property High Court (IPHC) rendered on March 25, 2016 which found that the above 4 Appellants’ (generic drug manufactures’) accused process for preparing a compound “Maxacalcitol”, which is used as a drug for treating keratosis, constituted a patent infringement of Chugai’s process patent²⁾ under the DOE. This is the first case where the Supreme Court decided on the DOE relating to a chemical process.

Specifically, under the established fact that there was a difference between the Chugai’s patent and the accused process in that the former defined the carbon skeleton of the starting material and the intermediate material as having a cis-structure of vitamin D, while the latter used the starting and the intermediate materials having a trans-structure thereof, the Supreme Court focused on and considered only the 5^th factor that “the DOE should not be applied when there are any special circumstances such as a case where the accused product and the like are intentionally excluded from the scope of a claim during a patent prosecution”, among 5 factors for finding a patent infringement under the DOE, which was generally ruled in the Supreme Court Decision of February 24, 1998 [Case No. 1994 (O) 1083]; and ruled as below:

Just because the Applicant did not describe in the claims an element relating to an accused product and the like where the element was different from an element defined in the claims in spite of the fact that the Applicant could have easily conceived the element at the time of filing, did not mean that there were any special circumstances.
However, when it could be objectively and apparently understood that the Applicant showed that the Applicant intentionally did not describe such element(s) in the claim(s) although the Applicant recognized the element(s) defined in the claims to be replaceable with the element(s) relating to the accused product and the like, it could be said that there were special circumstances.

On the basis of the above ruling, the Supreme Court decided that it could not be objectively and apparently understood that there were any circumstances that the Applicant showed that the Applicant did not describe the different element although the Applicant recognized the element to be replaceable.

Conclusively, the Supreme Court dismissed the generic drug makers’ appeal, and upheld the conclusion of the IPHC decision.
The Supreme Court’s decision is made final and binding.

1) Grand Panel: Grand Panel is convened to hear cases where it is necessary to virtually unify court decisions, or cases involving important issues, which is somewhat similar to en banc in CAFC of the U.S.A. Since the founding of the IPHC in 2005, 10 cases including the above case have been heard.

2) Corrected Claim 13 of the Chugai’s patent at issue claims as follows:

Claim 13. A process for preparing a compound having the following formula:

wherein n is 1, R₁ and R₂ are methyl, each of W and X is independently hydrogen or methyl, Y is O, and Z is a steroid ring structure of the formula: <snip>
or a vitamin D structure of the formula:

wherein … …
which comprises:
(a) reacting a compound having the following structure:

wherein W, X, Y and Z are as defined above,
in the presence of a base, with a compound having the following structure:

wherein n, R₁ and R₂ are as defined above, and E is an eliminating group,
to produce an epoxide compound having the following structure:

(b) treating the epoxide compound with a reducing agent to produce the compound; and
(c) recovering the compound so produced.

K&P’s CommentsThe above Supreme Court decision clarifies criteria of the “special circumstances” in the 5^th factor of the DOE. The criteria would be similar to so-called “intentional exclusion” or “file wrapper estoppel”.