The IP High Court asserted that “consisting of” should be interpreted as “comprising”

The IP High Court asserted that the term “consisting of” can be interpreted as a meaning that the composition comprises a third component in an appeal against a decision of invalidation trial by the Japan Patent Office for a patent directed to a pharmaceutical composition, and dismissed the appeal.

Claim 1 of the defendant’s patent reads as follows.
Claim 1: A pharmaceutically stable preparation of oxaliplatinum for the administration by the parenteral route, consisting of a solution of oxaliplatinum in water at a concentration of 1 to 5 mg/ml and having a pH of 4.5 to 6 ... .

In this regard, the plaintiff claimed that the term “consisting of” may be interpreted either as excluding or as including a third component in addition to oxaliplatinum and water, and thus the claims are not clear while demanding the invalidation trial. However, since the Japan Patent Office dismissed the demand, the plaintiff appealed against the decision of the Japan Patent Office at the IP High Court. The IP High Court asserted as follows.

“Description of claims should be reviewed and asserted to be clear or not by referring the specification and drawings in addition to claims, and also by considering the technical common knowledge shared by a person skilled in the art at the time of filing of the patent application, in a view point of whether the description is unclear to a level that the third party suffers an unreasonable loss due to the inappropriate description of the claims”. “[T]he term ‘consisting of A’ should be interpreted as ‘being established/ being constructed’ by using A as ‘raw material/ material/ constituent’. Accordingly, the term ‘consisting of’ means that A is essential component. However, the term cannot be interpreted as a meaning that the composition is consisting only of A, and the composition may exclude or include the third component”.

In this regard, the IP High Court asserted that the present invention should be interpreted as a composition that includes “solution of oxaliplatinum” as a constituent, but the present invention does not specify whether the composition includes a third component or not. In addition, referring to the technical common knowledge at the time of filing of the present application, IP High Court asserted that a pharmaceutical preparation often includes additives such as a stabilizer and pH adjuster in addition to an active ingredient. Thus, the IP High Court asserted that the term “consisting of” should be interpreted as “comprising” in the present case and the claims are clear.

(Reported by Koji WATANABE, Japanese Patent Attorney)