Generic Drug Product Development in Japan: Regulatory Updates During 2014-2019 and the Future.

The growth of healthcare cost is a serious issue in many countries. Generic drug products play an essential role in reducing healthcare costs because they are less costly than the innovator drug products. The regulatory review of generic drug products in Japan is conducted by the Pharmaceuticals and Medical Devices Agency (PMDA). This report introduces the activities of the PMDA from fiscal years 2014-2019. The number of approvals of new generic drug products and partial changes was trending downward. Alternatively, the PMDA conducted six types of consultation meetings to advise on development and application; the number of consultation meetings was increasing. Moreover, during this period, the Ministry of Health, Labour and Welfare issued two basic principles for ophthalmic dosage forms and dry powder inhaler drug products and revised the guidelines for bioequivalence. Finally, the future of generic drug product development and considerations to improve their regulation were discussed. More efforts will continue to enable a more efficient and rational generic drug product development and shortening of the review period for partial change approval.

Modernization and Strengthening of Bioequivalence Guidelines in Japan.

Until now, human bioequivalence (BE) studies were conducted based on the revised 'Guideline for Bioequivalence Studies of Generic Products' issued in 2012 by the Ministry of Health, Labour and Welfare (MHLW) in Japan. However, revisions of BE guidelines were required to account for the globalization of pharmaceutical development, new technology, and scientific rationales over the last 8 years. Therefore, the MHLW published the revised 'Guideline for Bioequivalence Studies of Generic Products' in 2020. In this article, we introduce the main revised contents, such as the addition of a fed-state BE study, reconsideration of the pilot study and add-on study, acceptance of foreign subjects in a BE study, and clarification of the requirement of a reference product. Furthermore, we compare the BE evaluations of generic oral solid dosage forms with those of the Pharmaceuticals and Medical Devices Agency (PMDA), the US Food and Drug Administration (FDA), and the European Medicines Agency (EMA).

Current Regulation for Bioequivalence Evaluations of Generic Ophthalmic Dosage Forms in Japan.

In Japan, the revised version of bioequivalence (BE) evaluations for generic drug products was made available in 2012; however, the scope of this guideline is mainly oral solid dosage forms. Other dosage forms have to be discussed regarding how to evaluate BE by applicants and regulators during consultation meetings or the review process. Recently, there has been an increase in developing generic drug products in various dosage forms in Japan. Therefore, the Pharmaceuticals and Medical Devices Agency (PMDA) must strengthen their efforts to establish methodologies for BE evaluations for various dosage forms, including those of ophthalmic drugs. In 2016, the Japanese Ministry of Health, Labour and Welfare (MHLW) issued "The basic principles of bioequivalence evaluations of generic ophthalmic aqueous solutions." This document presents recommendations for clinical endpoint BE studies or biowaiver options to evaluate the BE of generic ophthalmic aqueous solutions. However, this document has brought other issues to the forefront, such as the lack of feasibility of human BE studies for certain indications. Therefore, the PMDA, Japan Ophthalmic Pharmaceutical Manufacturer's Association, and BE experts discussed these issues for 2 years, which led to an update by MHLW in 2018 entitled "The basic principles of bioequivalence evaluations of generic ophthalmic dosage forms." This document describes methodologies for evaluating the BE of ophthalmic dosage forms including suspensions. This article introduces recently approved generic products of ophthalmic dosage forms in Japan, the basic principle of which was issued in 2018, and compares the BE evaluations between the PMDA and U.S. Food and Drug Administration.

Current Understanding of the Equivalence Evaluations for In Vitro Tests on Generic Dry Powder Inhaler Drug Products in Japan.

The Japanese Ministry of Health, Labour and Welfare issued the basic principles for bioequivalence evaluations of generic dry powder inhaler (DPI) drug products in 2016. This document presents the recommendations of the methodology for the effective development of generic DPI drug products. Based on this document, the Pharmaceuticals and Medical Devices Agency (PMDA) advises the efficient development in the consultation meeting with generic companies. The PMDA generally requires the data of in vitro tests, pharmacokinetics studies, and clinical endpoint studies for generic development. In vitro tests play a critical role in the development of the generic versions because these tests are used to predict the efficacy and safety of other populations on whom clinical endpoint studies have not been conducted. We are aware that some points need further discussion, such as the recommendations for at least four groups of stages (group 1: the induction port and pre-separator, group 2: greater than 5 µm, group 3: ranging from 3 to 5 µm, group 4: ranging from 0.8 to 3 µm) for in vitro tests of the generic DPI products. This article shows the current understanding and recommendations with respect to in vitro tests, particularly for at least four groups of stages.

Bioequivalence Evaluations of Generic Dry Powder Inhaler Drug Products: Similarities and Differences Between Japan, USA, and the European Union.

In Japan, the development of generic oral dry powder inhaler (DPI) drug products for marketing approval has recently increased. The Pharmaceuticals and Medical Devices Agency (PMDA) considers the required data for each drug product in the consultation meeting. However, guidelines for DPI drug products have been published by the US Food and Drug Administration and the European Medicines Agency. Recently, the basic principles of bioequivalence evaluations of generic DPI drug products were published in March 2016 by the Ministry of Health, Labour and Welfare. The document mainly outlines the current understanding regarding the bioequivalence evaluations of generic DPI drug products based on knowledge from PMDA consultation meetings. In this review, we compared the bioequivalence evaluations of DPI drug products among Japan, USA, and the European Union and discuss future development of generic DPI drug products in Japan.

Similarities and Differences of International Practices and Procedures for the Regulation for Active Substance Master Files/Drug Master Files of Human Use: Moving Toward Regulatory Convergence.

PURPOSE: A gap analysis survey of international practices for Active Substance Master Files (ASMFs)/Drug Master Files (DMFs) of human use was conducted as a project of the ASMF/DMF working group of the International Generic Drug Regulators Pilot (IGDRP) to identify similarities and differences among ASMF/DMF procedures of 10 IGDRP members and 2 observers. METHODS: We conducted a questionnaire survey and compared the following aspects: overall ASMF/DMF procedures, submission requirements for ASMFs/DMFs, assessment processes for ASMFs/DMFs, the technical requirements for active pharmaceutical ingredients (APIs), generation of assessment reports for ASMFs/DMFs, procedures for changing ASMF/DMF details, and Good Manufacturing Practice (GMP) inspection/certification of API manufacturers. Twelve organizations participated in this project: the Brazilian Health Surveillance Agency (Anvisa), the European Union (EU), Health Canada (HC), the Singapore Health Sciences Authority (HSA), the South African Medicines Control Council (MCC), the South Korean Ministry of Food and Drug Safety (MFDS), the Japanese Pharmaceuticals and Medical Devices Agency (PMDA), the Swiss Agency for Therapeutic Products (Swissmedic), the Taiwan Food and Drug Administration (TFDA), the Australian Therapeutic Goods Administration (TGA), the European Directorate for the Quality of Medicines & HealthCare (EDQM) (Observer) and the Prequalification Team (PQT) of the World Health Organization (WHO), which includes the PQT-Medicines (Observer). RESULTS: Although there were many similarities among the participating agencies surveyed, there were also differences that should be discussed such as assessment processes of ASMFs/DMFs and Technical requirements for APIs. CONCLUSIONS: These differences revealed by this survey will be key considerations in order to facilitate the filing of ASMFs/DMFs globally and to establish a framework for sharing and utilizing information related to ASMFs/DMFs among IGDRP members in the future. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Exposure of drugs for hypertension, diabetes, and autoimmune disease during pregnancy and perinatal outcomes: an investigation of the regulator in Japan.

Assessment of perinatal effects of drug exposure during pregnancy after approval is an important issue for regulatory agencies. The study aimed to explore associations between perinatal outcomes and maternal exposure to drugs for chronic diseases, including hypertension, diabetes, and autoimmune disease.We reviewed 521 cases of adverse reactions due to drug exposure during pregnancy who were reported to the Pharmaceuticals and Medical Devices Agency, a regulatory authority in Japan. The primary outcomes were fetal and neonatal death and malformation of infants. Associations between perinatal outcomes and exposure to each drug category for hypertension, diabetes, and autoimmune disease were evaluated using logistic regression analysis.Of the 521 cases (maternal age: 15-47 years; mean 32.3 ±â€Š5.5), fetal and neonatal deaths were reported in 159 cases (130 miscarriage; 12 stillbirth; 4, neonatal death; and 13 abortion due to medical reasons), and malformations of infants were observed in 124 cases. In contrast to the trend of association between diabetes with or without medication and fetal and neonatal death (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.17-1.36), exposure to oral antidiabetics tended to be associated with fetal and neonatal death (OR, 4.86; 95% CI, 0.81-29.2). Malformation tended to be correlated with exposure to angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (OR, 2.98; 95% CI, 0.76-11.7). This association showed trends opposite to that of the association with hypertension itself (OR, 0.42; 95% CI, 0.18-1.02) or overall antihypertensives (OR, 0.42; 95% CI, 0.15-1.13). Occurrence of multiple malformations was associated with exposure to biologics (OR, 8.46; 95% CI, 1.40-51.1), whereas there was no significant association between multiple malformations and autoimmune disease with or without medication (OR 1.07; 95% CI, 0.37-3.06).These findings suggest that drugs of different categories may have undesirable effects when used during pregnancy. However, the regulatory database was not originally designed to evaluate the causal associations between drug exposure and adverse drug reactions. The limitations of spontaneous reporting systems should be carefully taken into account. Further studies are needed to elucidate the effects of individual drugs in each category on perinatal outcomes.