Regulatory Aspects of Cell and Gene Therapy Products: The Japanese Perspective.

Regulations for regenerative medicine for human use, such as cell and gene therapy (CGT), have evolved in accordance with advancements in clinical experience, scientific knowledge, and social acceptance of these technologies. In November 2014, two acts, "The Act on the Safety of Regenerative Medicine" (ASRM) and the "Pharmaceuticals, Medical Devices, and Other Therapeutic Products Act" (PMD Act), came into effect in Japan. The responsibilities of medical institutions in ensuring the safety and transparency of such medical technologies are described under ASRM. The PMD Act provides the option of a new scheme for obtaining conditional and time-limited approval for CGT products. Overall, research and development on CGT products, especially gene therapy products, is progressing. New legislative frameworks have been designed to promote the timely development of new technologies and safe and effective CGT products for Japanese patients.

Historical Overview of Regulatory Approvals and PMDA Assessments for Biosimilar Products in Japan During 2009-2022.

A biosimilar product is defined as "a biological product that is highly similar to an existing, approved biological product (known as originator or reference product) in terms of structure, function, quality, and clinical efficacy and safety". Recently, biosimilar products have been actively developed around the world, and part of the reason for this is to combat the rapid growth of medical expenses in many countries, including Japan, the United States (US), and Europe. The use of biosimilar products has been promoted as a measure to address this issue. The review of marketing authorization applications for biosimilar products in Japan is conducted by the Pharmaceuticals and Medical Devices Agency (PMDA), which reviews the comparability of the quality, efficacy, and safety based on the data submitted by the applicants. As of December 2022, 32 biosimilar products have been approved in Japan. Through this process, the PMDA has gained much experience and knowledge regarding the development and regulatory approval of biosimilar products; however, details of the regulatory approvals for biosimilar products in Japan have not been reported until now. Therefore, in this article, we present the details of regulatory history and revised guidelines for approval of biosimilar products in Japan, questions and answers, other relevant notifications, and consideration for comparability evaluations for analytical, non-clinical, and clinical studies. In addition, we provide details about the approval history, number, and types of biosimilar products that have been approved between 2009 and 2022 in Japan.

Insights into the clinical development of regenerative medical products through a comparison of three cell-based products recently approved for limbal stem cell deficiency.

Three regenerative medical products for limbal stem cell deficiency (LSCD), a rare and intractable ocular surface disease, have recently been approved in Japan. To our knowledge, this is the first time multiple stem-cell-based medical products have been approved for the same ocular disease. Development plans and study designs for each product differ, resulting in differences in indications. Since cell-based products have a heterogeneous formulation and often target rare diseases, they require a flexible approach to development. This review article describes the status and prospects of the clinical development of regenerative medical products by summarizing the issues of the three products from the Pharmaceuticals and Medical Devices Agency (PMDA) standpoint. Implementing stem cell-based products is challenging, requiring scientific and flexible review by regulatory authorities. To overcome these issues in the development process, developers and regulatory authorities need to communicate and fully discuss study protocols from the early stage of development.

Regulatory Issues: PMDA - Review of Sakigake Designation Products: Oncolytic Virus Therapy with Delytact Injection (Teserpaturev) for Malignant Glioma.

In June 2021, the Ministry of Health, Labor and Welfare approved Delytact Injection as a regenerative medical product for oncolytic virus therapy. The active substance of Delytact Injection is teserpaturev, a genetically engineered herpes simplex virus type 1 (strain F) in which the α47 gene and both copies of the γ34.5 gene have been deleted and the infected cell protein 6 (ICP6) gene has been inactivated by the insertion of the lacZ gene from Escherichia coli. Delytact Injection, when intratumorally administered to patients with malignant glioma, is expected to exert the following effects: (1) the mutant virus selectively replicates in tumor cells and destroys the infected cells through the replication process, exerting a cytocidal effect, and (2) the administration leads to induction of tumor-responsive T cells, which activates antitumor immunity and thus prolongs the survival of patients with malignant glioma. A Japanese phase II study (Study GD01) was conducted in patients with glioblastoma who had residual or recurrent tumors after radiotherapy with concomitant temozolomide. In Study GD01, however, stable disease continued for an extended period in some patients with glioblastoma. Hence, Delytact Injection is expected to be effective to a certain level. In line with this, Delytact Injection has been approved as an option for the treatment of malignant glioma, with one of the 3 approval conditions including conducting a use-results comparison survey and resubmission of the marketing authorization application within the granted time period of 7 years, under the conditional and time-limited approval scheme described in Article 23-26 of Act on Securing Quality, Efficacy and Safety of Products Including Pharmaceuticals and Medical Devices.