The Intellectual Property High Court (“IPHC”) Grand Panel has awarded an injunction against generic drug companies’ drugs, finding infringement based on the doctrine of equivalents.

In its decision, the IPHC presented notable standards for debatable issues over the first and the fifth requirements of the doctrine of equivalents (“DOE”). The  first  requirement  of the DOE is that the difference between the accused product and the patent claim is not the essential part of the patented invention. The fifth requirement is that there are no special circumstances such as where the accused product was intentionally excluded from the scope of the patent claim in the patent application procedures.

The Appellee (the Plaintiff in the first instance, the “Plaintiff”) is a co-owner of a Japanese patent directed to a manufacturing method of Maxacalcitol, an active component of a medicine treating keratosis (the patent and the invention are respectively referred to as the “Patent” and the “Invention”). The Plaintiff brought a lawsuit seeking an injunction against the Appellants (the Defendants in the first instance, the “Defendants”) to stop them from importing and selling generic Maxacalcitol drugs (the “Accused Product”), arguing it was an infringement of the Patent under the DOE.

An outline of the Invention is as follows: initiating a chemical reaction between the starting material and reagent (of the patented manufacturing method) to produce an intermediate, then treating the intermediate with a reducing agent to obtain the target chemical substance containing Maxacalcitol. The Accused Product differs from the Invention in that the vitamin D structure composing the starting material and the intermediate is the “trans” form (which is the geometric isomer of the “cis” form vitamin D structure used for the Invention). The Plaintiff argued infringement under the DOE with respect to such difference in the cis-trans isomerism of the vitamin D structure.

The IPHC acknowledged that all of the five requirements of the DOE are satisfied and found the infringement under the DOE. The holdings with respect to the first and fifth requirements, which seem particularly notable in the decision, are as follows:

The first requirement

As for the first requirement, it was disputed whether the abovementioned difference (between the Accused Product and the Invention) in the cis-trans isomerism falls under the essential part of the Invention. On this point, the IPHC presented the following standards:

  1. The essential part of an invention shall mean the characteristic part constituting the unique technical idea non-existent in the prior art, among the description in the patent claim. If the degree of contribution by an invention is high when compared to the prior art, the essential part is to be identified as the superordinate concept of a part of the patent claim of the invention. On the other hand, if the degree of contribution by an invention is not so high, the essential part is to be identified as almost the same thing as described in the patent claim of the invention.
  2. Besides, if what is described as the previously unsolved problem in the patent specification is objectively insufficient in the light of the prior art at the time of the patent application, the characteristic part of the invention shall be identified taking account of the prior art not described in the patent specification as well. In such case, the essential part of an invention shall be closer to the description of the patent claim as such and the scope where infringement under the DOE is found shall become narrower, as compared to the case where the essential part of an invention is to be identified only based on the patent claim and specification of the invention.

As to the present case, the IPHC held that the problem to be solved by the Invention is to provide for a novel (i.e. being not disclosed in the prior art) manufacturing method of a vitamin D derivative having the side chain of Maxacalcitol, and that the Invention adopts, as a specific means to solve the problem, the method as described in the patent claim, whereby enabling the manufacture of the target chemical substance through a novel reaction path, and thus the degree of contribution by the Invention is high. The IPHC also held that the description of prior art in the specification of the Patent is not insufficient even in the light of prior art documents submitted by the Defendants. Based on this, the IPHC concluded that the first requirement is satisfied, holding that the abovementioned difference (between the Accused Product and the Invention) in the cis-trans isomerism does not fall under the essential part of the Invention.

The fifth requirement

With respect to the fifth requirement, the issue concerned the finding of “special circumstances” to negate infringement under the DOE, in such a situation where the different part between the accused product and  the patented invention comprises what the patent applicant would have easily conceived of at the time of the patent application. On this point, the IPHC has presented the following standards:

  1. Even if there is a certain composition which is substantially the same as, but not described in, the patent claim and the patent applicant would have easily conceived of that composition at the time of the patent application, the mere fact that the patent applicant failed to describe this certain composition in the patent claim does not constitute the “special circumstances” to negate infringement under the DOE.
  2. On the other hand, if it can be objectively and apparently found that the patent applicant had been aware that such composition (not described in the patent claim) could substitute for what is described in the patent claim, the fact that the patent applicant failed to describe the certain composition in the patent claim constitutes the “special circumstances” to negate infringement under the DOE.  For example, this could occur in a           situation   where   (a)   the   patent   applicant described (or is deemed to have described) in the patent specification the certain composition substituting for the claimed invention or (b) the patent applicant described, in an article published at or around the time of the patent application, the certain composition substituting for the claimed invention.

Applying the foregoing standards to the present case, the IPHC reviewed the descriptions in the specification of the Patent and other circumstances which the Defendants alleged to constitute the “special circumstances” of the fifth requirement, and concluded that the “special circumstances” did not exist because: (i) the specification of the Patent did not describe the patented manufacturing method using the “trans” form of the Vitamin D structure as the starting material; and (ii) evidence was not sufficient to objectively and apparently find that the patent applicant had been aware, at the time of the patent application, that the “trans” form of the Vitamin D structure could substitute for the “sis” form specified in the claim of the Patent.

This IPHC Grand Panel decision is notable in that it has provided for certain standards to judge on those debatable issues as mentioned above regarding the first and the fifth requirements of the DOE, and applied the standards to the specific facts in the present case to find infringement under the DOE. As the Defendants  have appealed the IPHC’s decision to the Supreme Court as of April 7 according to the IPHC, we would need  to  closely watch how the situation develops.