Decisions on Combination Drug Patent Infringement

In March 2025, the IP High Court handed down a decision on a patent infringement lawsuit. The patent owner, holding rights to a combination drug containing multiple ingredients, sued a surgeon who had used several drugs containing constituent ingredients of the patented combination drug in breast augmentation surgery. The Court found that the surgeon had mixed all the ingredients prior to administration, which constituted the “production” of the patented combination drug. It further held that the surgeon was not exempt from patent enforcement because the surgery was performed for cosmetic, rather than therapeutic purpose. This ruling reversed the Tokyo District Court’s decision, which had found no infringement. This article outlines both decisions and discusses issues relating to combination drugs and cosmetic/medical procedures.