Evaluation of drug lag and drug loss in Japan: participation in global phase III oncology trials - Abstract

Sep 23, 2026

Study examining drug lag and drug loss by analyzing Japan’s participation in global phase III multinational/multiregional clinical trials targeting cancer. Phase III MRCTs of anticancer drugs initiated between 2008 and 2022 were collected and participant countries, sponsor, design, and cancer type were analyzed using logistic regression. Findings quantify rising participation rates and identify factors linked to non-participation and participation. Conclusions address expected future impacts on unapproved drugs and recommend strategies for enabling smaller overseas companies to include Japan.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages9

Reading Time23 min

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Abstract

Introduction

Materials and methods

Criteria for trial selection

Data sources and collected information

International Journal of Clinical Oncology (2025) 30:1109–1117 [https://doi.org/10.1007/s10147-025-02756-8](https://doi.org/10.1007/s10147-025-02756-8) Evaluation of drug lag and drug loss in Japan: participation in global phase III oncology trials Kaname Shiga1,3 · Taro Shibata2 · Toshio Miyata1 Received: 14 November 2024 / Accepted: 23 March 2025 / Published online: 11 April 2025 © The Author(s) 2025 Abstract Background Despite efforts to mitigate drug lag, discrepancies in drug approval timelines persist between Japan and the US, and increase in unapproved drugs has become a significant challenge. This study aimed to evaluate potential drug lag and drug loss by assessing Japan’s participation in global phase III multinational/multiregional clinical trials (MRCTs) targeted cancers. Methods Phase III MRCTs of anticancer drugs initiated between 2008 and 2022 were collected. Information of participant countries, study sponsor, study design, and cancer type were collected and analyzed by logistic regression analysis to identify factors affected Japan’s participation. Results Of 999 phase III MRCTs, Japan’s participation every 5 years increased over 15 years (2008–2012: 34.3%, 2013–2017: 51.6%, 2018–2022: 60.2%), while Japan’s non-participation numbers did not change (2008–2012: 157, 2013–2017: 167, 2018–2022: 165) . In the multivariate logistic regression analysis, the absence of an operational base in Japan and minor cancers were negatively associated with Japan’s participation in phase III MRCTs. Japan’s participation was also associated with some cancer organs and drug modalities. Conclusion Potential future drug lag and increases of unapproved drugs were expected to increase. Since the inclusion of Japan in MRCTs results in shorter or no approval lag, Japan should promote to make circumstances where small overseas companies can include Japan in MRCTs. Keywords Drug lag · Drug loss · Anticancer drug development · MRCT · Phase III Introduction Cancer is a serious and fatal disease, accounting for approximately 25% of all deaths in Japan [1], and it is reported that 65.5% of Japanese men and 51.2% of women will be diagnosed with cancer during their lifetime [2] . As a result, there is a need for new and innovative drugs to improve the prognosis of cancer patients, and clinical development of anticancer drugs is active in Japan and overseas. * Kaname Shiga [kaname.shiga.med@gmail.com](kaname.shiga.med@gmail.com) 1 Cooperative Major in Advanced Biomedical Sciences, Joint Graduate School of Tokyo Women’S Medical University and Waseda University, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan 2 Biostatistics Division, Center for Research Administration and Support, National Cancer Center, Tokyo, Japan 3 Medical Affairs Division, Johnson & Johnson, Tokyo, Japan However, there is a difference in the timing of anticancer drug approvals between Japan and other countries, particularly the US. This problem is known as “drug lag” and is a serious issue because it affects patient access to medicines, especially anticancer drugs [3, 4] . From the late 2000s to the early 2010s, the Ministry of Health, Labour and Welfare (MHLW) issued several guidelines and notifications to promote the use of multinational/ multiregional clinical trials (MRCTs) to support the marketing authorization of new drugs in Japan [5–7] . In recent years, the development of clinical trial systems and expansion of capabilities of the Pharmaceuticals and Medical Devices Agency (PMDA) system have narrowed the gap between Japan and the US in the development of anticancer drugs [8, 9], but the issue of “drug loss”, where drugs are not developed since there are no companies to develop them in Japan and the number of unapproved drugs increases in the future, has become a major challenge [10, 11] . Previous reports have shown that Japanese participation in MRCTs is associated with both drug submission and approval l

FAQs

What is the study’s main objective regarding drug lag and drug loss?

To evaluate potential drug lag and drug loss by assessing Japan’s participation in global phase III multinational/multiregional clinical trials targeting cancers.

How were the phase III trials selected and what time window was used?

Phase III MRCTs of anticancer drugs initiated between 2008 and 2022 were collected, with inclusion and exclusion criteria based on funding, participant country structure, cancer targeting, and trial leadership.

Which factors were associated with Japan’s participation in phase III MRCTs?

Absence of an operational base in Japan and minor cancers were negatively associated with participation, and participation was also linked to certain cancer organs and drug modalities.

Sep 23, 2026

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