Regarding the Pravastatin case in which the product-by-process claim (PBPC) construction is at issue, the Japan Supreme Court reversed the Grand Panel decision of the Intellectual Property (IP) High Court and remanded the case for trial on June 5, 2015. The impact of this decision on patent practice can be summarized as follows.
First, the Supreme Court adopted the Identical Product Theory for the PBPC construction at an infringement (trial) stage while the IP High Court had adopted the Process Limitation Theory. Specifically, the Supreme Court ruled that "even when the product claim contains its production process, the scope of the PBPC should be construed to correspond to a product which is identical to the product produced by the production process in light of identicalness in structure, properties, etc."
Second, the Supreme Court pointed out that the PBPC is not in the appropriate claim format, thus ruling that the PBPC is considered to satisfy the clarity requirement "only when it is impossible or impractical to identify the product directly by its structure or property." Therefore, if a PBPC does not satisfy the above exception, it is treated as failing to meet the clarity requirement. This means that JP patents containing PBPCs may be challenged by invalidation trials or treated as invalidated patents in infringement courts. Since the JPO had applied the clarity requirement to the PBPCs in a relaxed manner, a considerable number of JP patents containing PBPCs may be risking invalidation.
Thirdly, in Japan, the same theory, i.e., the Identical Product Theory, will be applied not only to PBPCs in the examination stage but also to those in the infringement (trial) stage. In other words, as the supplemental opinion of the Supreme Court decision suggested, "a common, unified framework for PBPC construction" is now being adopted for PBPC construction in Japan, and it is a framework diverging from the U.S. practice.