On August 28, 2019, the Supreme Court (SC) of Japan issued a decision regarding the inventive step of pharmaceutical subject matter. To the best of our knowledge, the SC has never issued a decision that directly addresses inventive step in the field of life science including pharmaceuticals. In this arguably unprecedented case (H30, Gyo-ke, No. 69), which is an appeal against an IP High Court (IPHC) decision denying a first instance decision (invalidation proceedings) of the Japan Patent Office, the validity of the IPHC’s ruling that it could not be acknowledged that the subject matter under dispute directed to a new, but obvious use of a certain known compound leads to an unexpected technical effect (pharmacological effect) was disputed.
 
The SC denied the IPHC ruling, stating that it was merely based on the IPHC’s finding that the same level of the same pharmacological effect as that of a claimed compound was known to be achieved by other compounds that are structurally unrelated to this compound; and that such a basis alone is not sufficient for denying the existence of an unexpected technical effect. The case has been remitted back to the IPHC.