Current Status and Open Issues Concerning Global Clinical Trials (GCTs) in Japan and East Asia

Diversity in Oncology Clinical Trials: Current Landscape for Industry-Sponsored Clinical Trials in Asia

INTRODUCTION

There has been a growing recognition on the importance of diversity in clinical trials. Existing research has highlighted a significant demographic imbalance. Amidst this renewed focus on diversity, it is crucial to acknowledge that Asia comprises over half of the world's population. Given the region's demographic significance, we sought to compare various characteristics and growth rates for trials with sites in Asia against those without any sites in Asia.

METHODS

We performed comprehensive analyses of industry-sponsored phase 2 and 3 oncology trials registered at Clinicaltrials.gov, using drugs or biologics as investigational agents and executed between 1 January 2018 and 31 December 2022. We applied the compound annual growth rate (CAGR) as an analytical tool to track the trial growth rates over this 5-year period.

RESULTS

We identified 894 industry-sponsored phase 2 and 3 cancer studies with available study location data. Out of these, 415 trials (46.42%) had study sites in Asia. Notably, these trials with sites in Asia were also more likely to be phase 3 trials (39.76% vs 6.47%, p < 0.001), include female and paediatric populations, and be randomised trials. Interestingly, lung and stomach cancers were more commonly studied in these trials, while myeloma was less commonly studied. The number of trial sites for liver cancer was not significantly higher for Asia, even though the incidence of the disease is much higher in this region. Despite an overall declining trend in the number of clinical trials in the last 5 years, we observed a transitional positive increase in the CAGR from 2020 to 2021 for trials with sites in Asia. However, East Asia, specifically China, exhibited a disproportionate overrepresentation in these trials.

CONCLUSIONS

There are notable characteristics of clinical trials with sites in Asia. Comprehending these disparities may aid in the strategic planning to enhance a balanced representation of ethnicities in trials.

Characteristics of Asian Participation in Multi-regional Clinical Trials Reviewed for Drug Approval in Japan: Opportunities for Collaboration Between South-East Asia, East Asia, and Japan

Although the percentage of multi-regional clinical trials (MRCTs) submitted for drug approval in Japan increased significantly since the 2007 publication of the regulatory guideline, "Basic principles on global clinical trials", strategic collaborations between Asian countries will be important to promote MRCTs in accordance with the ICH E17 guideline published in 2017. In this study, characteristics of MRCTs reviewed for drug approval in Japan, especially those with participation by South-East Asia and East Asia, were investigated to explore opportunities for collaborations on global drug development in Asia. More than 90% of reviewed trials were conducted as global MRCTs. In addition to Japan, South-East Asia has participated in various types of MRCTs in terms of total numbers of subjects and countries. However, South-East Asia participation was lower in large-size MRCTs (total sample size ≥ 1000) than in middle- (500 ≤ total sample size < 1000) and small-size MRCTs (total sample size < 500). Furthermore, similar clinical trials for the same indications to the MRCTs without South-East Asia were rarely conducted separately in South-East Asia. Participation of other Asian countries did not affect the percentage of Japanese subjects enrolled in an MRCT, but did significantly increase the percentage of participating Asian subjects. These results suggest that additional opportunities for collaboration on MRCTs may be possible between Japan and other Asian countries, especially more collaborations with South-East Asia in the large-size MRCTs. More data of Asian populations from MRCTs will be useful for exploring an important ethnic factor affecting drug response, and will provide a sound scientific basis in considering the application of the pooled data concept in Asia, as described in the ICH E17 guideline.

Efficacy Comparison for a Schizophrenia and a Dysuria Drug Among East Asian Populations: A Retrospective Analysis Using Multi-regional Clinical Trial Data

BACKGROUND AND OBJECTIVES

Multi-regional clinical trials (MRCTs) are an efficient drug development strategy for eliminating drug lag in East Asian countries. In planning MRCTs according to the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use E17 guideline, it is expected that East Asian populations with relatively similar ethnicity can be pooled as one population. However, evidence supporting this assumption is limited. This study aimed to investigate population/regional differences considering influencing factors among East Asian regions using MRCT data as a research model.

METHODS

A retrospective analysis was conducted to determine the efficacy of two drugs, asenapine, a schizophrenia drug, and tadalafil, a dysuria drug for benign prostatic hyperplasia, using MRCT data from Japan, Korea, and Taiwan. First, predictive factors and effect modifiers were evaluated. Then, population/regional differences were evaluated using multivariate regression models, with the interaction term Region-by-Treatment group and adjustment for influencing intrinsic/extrinsic factors.

RESULTS

Among the 4 outcomes for the two drugs, no significant population/regional differences were detected (P > 0.05) by the adjusted regression models. The effect modifiers, such as pretreatment drug status or concurrent diseases, were common among countries.

CONCLUSIONS

No significant population/regional efficacy differences were found for the two drugs among the three regions. This finding supported the possible applicability of the region pooling strategy for MRCTs in East Asia, emphasizing the benefits of exploring ethnic difference/influencing factors at an early stage to design further confirmatory studies. However, further evidence for various drugs should be accumulated.

Analysis of Pediatric Drug Approval Lag in Japan

BACKGROUND

Drugs should be made available to all patients in a timely manner regardless of whether they are adults or children. In contrast to the United States (US) and the European Union (EU), no laws mandating pediatric drug development have been established in Japan. The objective of this study was to examine the current status and characteristics of pediatric drug development in Japan using information on the approval lag for pediatric indications between Japan and the EU.

METHODS

Drugs approved for pediatric indications between January 2007 and December 2018 in Japan were studied. The approval lag for pediatric indications between Japan and the EU was calculated and analyzed by approval time and the Anatomical Therapeutic Chemical (ATC) classification. Factors potentially affecting the approval lag, such as orphan drug status, company nationality, and clinical data package, were examined.

RESULTS

The median approval lag for 105 drugs with pediatric indications in both Japan and the EU was 1017 days (Japan was behind). The lag for ATC category B improved significantly after 2011, and for category L after 2015; the medians were less than half a year. The lag for drugs developed globally via multi-regional clinical trials was significantly shorter compared with drugs developed regionally.

CONCLUSION

Global clinical trials are the most effective means of shortening approval lag time in pediatric drug development. Global development is making rapid progress for many adult diseases, thereby creating an environment for proactive participation in global clinical trials even for pediatric drugs. For further improvement, more active drug development for pediatric indication is recommended in tandem with the US and the EU.

Population/regional differences in efficacy of 3 drug categories (antidiabetic, respiratory and psychotropic agents) among East Asians: A retrospective study based on multiregional clinical trials

AIMS

This study aimed to identify population/regional differences in drug efficacy and the influencing factors among East Asians to be considered when planning multiregional clinical trials (MRCTs) to facilitate rapid drug approval in Asians.

METHODS

A retrospective analysis of efficacy (intergroup difference in endpoint between control and study drug treatment) among East Asian populations for 3 drug categories, antidiabetic, respiratory and psychotropic agents, was conducted in collaboration with pharmaceutical companies using their MRCT data. Common endpoints by drug category were selected; background factors that commonly affected the endpoints among regions were analysed first; then the population/regional differences were evaluated by the interaction term region-by-treatment using an analysis of covariance model after adjusting for background factors.

RESULTS

Among 17 endpoints for eight pharmaceutical products from 3 drug categories, no substantial population/regional differences were detected in the 3 drug categories examined (P > .05), except for haemoglobin A1c change between Japan and Korea for an antidiabetic drug, insulin glulisine (P = .0068). However, no such regional differences were evident in patients with clinically important higher haemoglobin A1c baseline values (majority subgroup). Variability in disease severity at baseline and concomitant drugs were determined to be potential influencing factors for regional differences.

CONCLUSIONS

This study suggests that the regional variability in efficacy of these 3 drug categories is not large among East Asians, and reveals the importance of considering background factors when planning MRCTs. Further studies are needed to evaluate regional variability in the efficacy of other drug categories and clarify the factors leading to regional differences in East Asians.

Strategic inclusion of regions in multiregional clinical trials

Background

With the recent publication of the International Conference on Harmonisation E17 guideline and major reforms in China underway, the platform for clinical trial conduct is expected to change. This study aims to assess the strategic inclusion of regions in clinical trials and its change in trends over the past decade.

Methods

The ClinicalTrials.gov registry was searched for clinical trials registered by the top 10 pharmaceutical companies between 1 January 2008 and 31 December 2017. Extracted data included phase, disease type, intervention, study start year, and region. Trial type was classified as either a local study or a multiregional clinical trial as per the International Conference on Harmonisation E17 guideline.

Results

Of 2488 phase I, 1855 phase II, and 1999 phase III trials included, the majority of phase I trials were local studies (76.8%), while the majority of phase II (66.0%) and phase III (72.2%) trials were multiregional clinical trials. The proportion of multiregional clinical trials showed an increasing trend for all phases ( p < 0.01). Although North America and Europe remained the main locations, increasing trends of inclusion of other regions, such as East Asia, were noted.

Conclusion

Globalization of drug development is evident with the increasing trend of multiregional clinical trial. Regulatory authorities as well as the pharmaceutical industry should prepare for the evolving setting of clinical research and problems that can arise from these changes.

How Does "Regulatory Practice" Create Discrepancies in Drug Label Information Between Asian and Western Countries? Different Label Information for Direct Oral Anticoagulants Approved in the United States, Europe, Korea, and Japan

Globalization of the pharmaceutical industry has continued over the past few decades, and various regulatory authorities have put considerable effort into harmonizing and standardizing drug regulations. However, the regulatory practices of each regulatory authority, in addition to local differences in ethnic, social, and cultural backgrounds, create discrepancies in risk/benefit assessments, regulatory decisions, and drug label information in various countries. This study examines discrepancies in the label information for direct oral anticoagulants approved in the US, Europe, Korea, and Japan and reviews the causes of those discrepancies, focusing on regulatory practices. Although the label information for each direct oral anticoagulant in all 4 regions was supported by the same global, pivotal clinical data, it differed depending on regulatory authorities' judgments about the risk/benefit balance, which were based on their own requirements, regulations, perspectives on making regulatory decisions, and regulatory approval experiences, in addition to their review of the scientific data. In particular, the Korean Ministry of Food and Drug Safety and Japanese Pharmaceuticals and Medical Devices Agency have taken a comparatively conservative stance, with more emphasis on safety than on efficacy compared with regulatory authorities in western countries, because of the double threshold in their regulatory practice. Our findings suggest that drug label information in various regions will not be equal as long as differences in regulatory practice and non-regulatory factors exist among regulatory authorities. Also, those differences should be considered in order to streamline global drug discovery, development, and approval.