Regulatory and clinical development to support the approval of advanced therapies medicinal products in Japan

Introduction: A new category of products, i.e. regenerative medicine products (RPs), has been defined for advanced therapies medicinal products in Japan, as well as a legislative and regulatory framework to promote their clinical development. Areas covered: This review analyses the most relevant features of the regulatory strategies and clinical development that led RPs to their approval in Japan. Expert opinion: As of 31^st September 2021, a total of 14 RPs were approved for 16 indications. From a regulatory standpoint, the available designations allow attractive benefit packages that promote the development of innovative products in Japan and is one of the key points to consider when the global regulatory strategy for the product is being developed. RPs regulations in Japan allow adaptive licensing and constitute shortcut through the clinical development to the approval. RPs have been mainly approved so far based on small studies with inconclusive and limited evidence of efficacy and safety, prioritizing the unmet medical needs of the target diseases, and therefore, the early access for patients. This review also compares the regulatory and clinical development for the current approved RPs in Japan with the development trends in the European Union and United States of America.