Patent linkage and the rule of law in the context of pharmaceutical marketing approval in Japan

Abstract This article critically examines Japan’s patent linkage system, which allows the Ministry of Health, Labour and Welfare (MHLW) to withhold marketing approval for generic drugs if they infringe the patent rights of originator drugs. Although the system is broadly aligned with Japan’s obligations under the TPP11 Agreement, it lacks statutory authorization and is based solely on non-binding administrative notices. This raises serious concerns regarding the rule of law, particularly in relation to legality and procedural fairness. The article argues that neither the Pharmaceuticals and Medical Devices Act nor any other statute, including the Patent Act, permits the MHLW to consider patent rights as a ground for withholding approval. The commonly cited policy objective of ensuring a stable supply of generics is not recognized in the statute and cannot justify this practice. The current framework also lacks an adequate mechanism for judicial review. Through analysis of cases such as Nipro v Eisai and Samsung Bioepis, the article shows how courts have either dismissed declaratory actions or issued non-binding findings, resulting in asymmetrical procedural outcomes. These shortcomings highlight the need for systemic reform. The article proposes two alternatives: (i) a bilateral procedure before the Japan Patent Office, followed by judicial review, or (ii) a statutory cause of action allowing parties to seek declaratory judgments in civil court. Both models would require procedural safeguards and access to patent information. Ultimately, the article concludes that meaningful judicial review must be incorporated to align the system with constitutional principles and the rule of law.