[IP Newsletter] Decision by the IP High Court regarding average molecular weight and the clarity of claims requirement

We are pleased to announce the February 2017 issue of Sonderhoff & Einsel IP Newsletter.


The plaintiff, X, filed an invalidation trial against a patent held by defendant ROHTO Pharmaceutical
Co. Ltd. which claimed a violation of the clarity of claims requirement based on the lack of clarity of
the “average molecular weight” in the claims. The JPO, however, made a decision to maintain the
The plaintiff was not satisfied with the decision by the JPO and appealed to the Intellectual Property
High Court, which led to the JPO’s decision being denied.
The subject matter of the present patent was a “refreshing composition for ophthalmology”
containing chondroitin sulfate or a salt thereof which has a specific average molecular weight. The
defendant filed a patent application in 2005, and the establishment of the patent right was
registered in 2013.


For details, please check the following PDF.

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