Multiregional Clinical Trials Research Articles

An Empirical Analysis of Japan's Drug Development Lag Behind the United States.

The "drug lag" (ie, the approval lag for new drugs) hinders patients' access to innovative new medicines. The drug lag was heavily debated in Japan from the late 2000s to the early 2010s. It consists of "development lag" (ie, the submission date lag for new drug applications) and "review lag" (ie, the difference in review periods). As the 2 lags have different causes and display significantly different recent trends in Japan, we focus on the development lag-in contrast with most previous literature-between Japan and the United States, based on a database we created for all new drugs from 2008 to 2018 using publicly available data sources. First, we found that Japan's development lag relative to the United States did not shrink in terms of the overall distribution rather than the median, which was the focus of most prior studies. Second, we examined the factors (product characteristics) that significantly affected the development lag and found that products that underwent multiregional clinical trials and those that were certified as "breakthrough therapies" in the United States had significantly shorter development lags with high robustness, whereas products receiving price premiums did not. Finally, we discussed the policy implications of these results. For instance, innovative new drugs that are presumed to receive price premiums require enhanced policy support for early application from the initial stages of clinical trials. It is also essential to promote information sharing regarding evaluations by foreign reviewing authorities for efficient use in the home country.

Japan’s Participation in Multi-regional Clinical Trials: Analysis on Trials Sponsored by Major Foreign-affiliated Companies

Japan’s Participation in Multi-regional Clinical Trials: Analysis on Trials Sponsored by Major Foreign-affiliated Companies

Use of likelihood estimates for variances for the design and evaluation of multiregional clinical trials with heterogeneous variances.

Globalized drug development studies, such as multiregional clinical trials (MRCTs), have attracted much attention due to their ability to expedite drug development and shorten the time lag of drug release. While observing the overall effect of a new drug, the region-specific effects to support drug registration in constituent regions can also be evaluated. Several challenges arise in conducting MRCTs, such as the heterogeneity in the variability of the primary endpoint across regions. However, most of the existing statistical methods assume a common variability, which may not be valid in practice due to differences across regions (eg, diversities in ethnicity or disparities in medical culture/practice). We present a statistical method for the design and evaluation of MRCTs to consider the heterogeneous variability across regions. We assessed the overall sample size requirement and addressed the region-specific sample size determination to establish the consistency of treatment effects between the specific region and the entire group. We demonstrate the proposed approach with numerical examples.

Diversity and Inclusion in Drug Development: Rethinking Intrinsic and Extrinsic Factors with Patient Centricity.

Diversity and Inclusion in Drug Development: Rethinking Intrinsic and Extrinsic Factors with Patient Centricity.

Co-Development of Oncology Drugs and Companion Diagnostics: Analyses of Approval Lags and Drug Development Periods in Recently Approved Cases in Japan.

The utilization of biomarkers has become increasingly active to enhance efficiency of clinical development. This study evaluated the current situation and quantitative impact of co-development of companion diagnostics (CDx) on the oncology drug development in Japan. Based on publicly available information about the oncology drugs and CDx approved in Japan in 2010-2020, we evaluated the approval lag time between drugs and CDx, and the duration between the pivotal study start date and the new drug application submission date (the time to application). Influences of multiple factors including the use of CDx on the time to application were also analyzed. A diagnostic test was mostly used from an early development phase such as phase1/2 study, and the median approval lag has tended to decrease when approved CDx were used (- 507 vs. - 25days for newly developed CDx). The shorter median times to application were observed in Drugs with CDx (1204days) compared to Targeted therapies without CDx (1423days) or Other drugs without CDx (1853days), although both the cancer types and the implementation of multi-regional clinical trials have a larger impact on the time to application compared to the use of CDx. The use of CDx from the early development phase and the global development strategy could have a positive contribution on the development period of oncology drugs, which will facilitate patients' earlier access to the optimal treatment.

The necessary conduct: Exploratory multiregional clinical trials in East Asia.

Various studies have highlighted the importance of ethnic differences. The consideration of ethnic differences in the field of individualized pharmacotherapy is imperative. Therefore, various organizations and networks across countries should aim to conduct multicountry and multiregional clinical trials (MRCTs). If there is solid evidence available to evaluate the existence of ethnic differences between the same regional areas, it will lead to an increase in the efficiency of drug development. The purpose of this paper was to compare the approval dosing regimen among four Asian countries (Korea, Japan, China, and Taiwan) and elucidate the readiness and current status of the implementation of the International Conference on Harmonization (ICH) E17 guidelines on MRCTs. Reducing unnecessary clinical trials via multinational clinical trials in East Asian countries is also suggested. The approved dosing regimens for some drugs in the four Asian countries were similar; however, some differences might be caused by differences in legislation, even though there were no ethnic differences. This indicates that there are several roles to be expected of the Asia Clinical Pharmacology study network for exploratory MRCTs, which would lead to the accumulation of evidence for MRCTs, ultimately accelerating the efficiency of drug development in East Asian countries. The exposure of the new treatment to the necessary patients through collaborative research coordination and simultaneous multinational subject recruitment would serve its role in providing East Asia with specific personalized medicine with a high treatment success rate.

Robust estimates of regional treatment effects in multiregional randomized clinical trials with semiparametric logistic model.

In multiregional randomized clinical trials (MRCTs), determining the regional treatment effect of a new treatment over an existing one is important to both the sponsor and related regulatory agencies. Also of particular interest is to test the null hypothesis that the treatment benefit is the same among all the regions. Existing methods are mainly for continuous endpoint and use parametric models, which are not robust. MRCTs are known for facing increased variation and heterogeneity and a robust model for its design and analysis would be desirable. We consider clinical trials with a binary primary endpoint and propose a robust semiparametric logistic model which has a known parametric and an unknown nonparametric component. The parametric component represents our prior knowledge about the model, and the nonparametric part reflects uncertainty. Compared to the classic logistic model for this problem, the proposed model has the following advantages: robust to model assumption, more flexible and accurate to model the relationship between the response and covariates, and possibly more accurate parameter estimates. The model parameters are estimated by profile maximum likelihood approach, and the null hypothesis of regional treatment difference being the same is tested by the profile likelihood ratio statistic. Asymptotic properties of the estimates are derived. Simulation studies are conducted to evaluate the performance of the proposed model, which demonstrated clear advantages over the classic logistic model. The method is then applied to analyzing a real MRCT.

Bayesian multiregional clinical trials using model averaging.

Multiregional clinical trials (MRCTs) provide the benefit of more rapidly introducing drugs to the global market; however, small regional sample sizes can lead to poor estimation quality of region-specific effects when using current statistical methods. With the publication of the International Conference for Harmonisation E17 guideline in 2017, the MRCT design is recognized as a viable strategy that can be accepted by regional regulatory authorities, necessitating new statistical methods that improve the quality of region-specific inference. In this article, we develop a novel methodology for estimating region-specific and global treatment effects for MRCTs using Bayesian model averaging. This approach can be used for trials that compare two treatment groups with respect to a continuous outcome, and it allows for the incorporation of patient characteristics through the inclusion of covariates. We propose an approach that uses posterior model probabilities to quantify evidence in favor of consistency of treatment effects across all regions, and this metric can be used by regulatory authorities for drug approval. We show through simulations that the proposed modeling approach results in lower MSE than a fixed-effects linear regression model and better control of type I error rates than a Bayesian hierarchical model.

A critical appraisal of Japan's new drug approval process: a case study of FLT3-ITD inhibitor quizartinib.

In the last two decades, simultaneous global development of novel drugs become more common by conducting multiregional clinical trials. However, regulatory authorities of different regions often make different decisions on the approvals of the same new drugs. We would like to discuss the appropriateness of Japanese regulatory approach through a case study of quizartinib, a novel anti-leukemia drug developed in Japan. The pivotal clinical trial "QuANTUM-R" conducted in 19 countries showed a modest increase in median overall survival with quizartinib than the conventional chemotherapy. However, because several critical defects in this trial were pointed out by the United States Food and Drug Administration (US FDA) and the European Medicines Agency (EMA), quizartinib has not been approved in the US and Europe to date. On the contrary, the regulatory authority of Japan gave a notice of approval to quizartinib as a "standard of care", and the country becomes the sole country that granted market authorization. In our paper, we provide more detailed discussion about the methodology for scientific evaluation of the new drug.

A Sponsor’s View on Postmarketing Regulatory Commitments Involving Human Drug Products

A Sponsor’s View on Postmarketing Regulatory Commitments Involving Human Drug Products

Evaluation of Drug Lags in Development Initiation, New Drug Application and Approval Between Japan and the USA and the Impact of Local Versus Multi-regional Clinical Trials.

Drug time lags occur between the date that new drugs are first approved, often in the USA, and approval is granted in other countries. Multi-regional clinical trials (MRCTs) are a key strategy for simultaneous global development and regulatory submission of new drugs. However, no studies have evaluated the impact of MRCT versus local development on key time points in the drug development lifecycle between the USA and Japan. It is important for pharmaceutical companies planning drug development in Japan to understand when they can start development, when they can catch up in case of development initiation delay, length of time the development period might take, and amount of time that market exclusivity is lost, if Japan does not participate in the MRCT. The aim of this study was to investigate differences in drug lag in development initiation, New Drug Application (NDA) submission and drug approval, as well as differences in the development and review periods, by local trials and MRCTs between Japan and the USA. We also assessed the advantages and disadvantages of MRCTs for these lags in Japan. We analyzed drug approvals in Japan between 2016 and 2020 and divided them into local and MRCT groups. Lags in development initiation, NDA submission, and approval of new drugs were calculated by subtracting each date in Japan from the corresponding date in the USA. Our study period was divided into three periods based on the International Conference on Harmonization (ICH) E17 guideline, published in 2017, and the guideline for the Phase I trials in the Japanese population prior to MRCTs, published in 2014. In addition, subgroup analyses by therapeutic area, regulatory background, modality, capital style, and sales ranking (2020) were conducted. We analyzed 174 approvals in Japan and the USA. The differences in the drug lags for development initiation, NDA submission, and approval between the local and MRCT groups were 4.9, 3.5, and 3.2 years, respectively. All three lag times were shorter for the MRCT group than the local group. A development initiation lag in the local group has expanded since publication of the guidelines. For the people of Japan, important drug lags were identified in development initiation, NDA submission, and drug approval dates between local trials and MRCTs that include Japan. It is difficult to recover fully from the delay caused by local development, and it is important to understand the further expansion of drug lags, in cases where Japan is not involved in the MRCT.

Evaluation of Consistency of Treatment Response Across Regions-the LEADER Trial in Relation to the ICH E17 Guideline.

The US Food and Drug Administration in 2008 required new type 2 diabetes (T2D) medications to be subject to cardiovascular outcomes safety requirements. Accordingly, the global LEADER trial investigated cardiovascular outcomes of T2D treatment with liraglutide, a glucagon-like peptide-1 receptor agonist. LEADER (NCT01179048) was a multiregional clinical trial (MRCT) conducted from 2010 to 2016, thus completed before publication of the International Council for Harmonization (ICH) E17 guideline on MRCTs in 2017. Novo Nordisk pre-specified analysis of regional cardiovascular outcomes of LEADER participants. This paper assesses the pre-specified regional outcomes based on the ICH E17 guidelines on consistency evaluation. Regional LEADER participant numbers were broadly aligned with ICH E17 guidance and equally balanced across Europe, Asia, North America, and rest of the world. Overall primary major adverse cardiovascular events (MACE) composite outcome for the trial: hazard ratio (HR) (95% CI) 0.87 (0.78; 0.97); regional results varied, ranging from HR (95% CI) 0.62 (0.37; 1.04) (Asia) to 1.01 (0.84; 1.22) (North America). However, pre-specified Cox proportional-hazard regression analyses did not show clear evidence of interaction between regions and primary outcome (p = 0.20). Furthermore, post hoc analysis of the US population in the North American region found that adjusting for extrinsic or intrinsic factors did not account for this difference [HR (95% CI) 1.03 (0.84; 1.25)]. LEADER data evaluation demonstrated general consistency in cardiovascular safety across regions, except for US participants. Discrepancies in the North American region may relate to drug exposure or chance, but, as these were post hoc findings, the overall primary result is valid, aligned with ICH E17 guidelines.

Bayes shrinkage estimator for consistency assessment of treatment effects in multi-regional clinical trials.

The primary objective of a multi-regional clinical trial is to investigate the overall efficacy of the drug across regions and evaluate the possibility of applying the overall trial result to some specific region. A challenge arises when there is not enough regional sample size. We focus on the problem of evaluating applicability of a drug to a specific region of interest under the criterion of preserving a certain proportion of the overall treatment effect in the region. We propose a variant of James-Stein shrinkage estimator in the empirical Bayes context for the region-specific treatment effect. The estimator has the features of accommodating the between-region variation and finiteness correction of bias. We also propose a truncated version of the proposed shrinkage estimator to further protect risk in the presence of extreme value of regional treatment effect. Based on the proposed estimator, we provide the consistency assessment criterion and sample size calculation for the region of interest. Simulations are conducted to demonstrate the performance of the proposed estimators in comparison with some existing methods. A hypothetical example is presented to illustrate the application of the proposed method.

Hierarchical Generalized Linear Models for Multiregional Clinical Trials

Multiregional clinical trials have a hierarchical data structure because several regions form a patient population and individual patients are nested within their own regions. Data are obtained from two different levels: regions and patients. To incorporate such a hierarchical structure, hierarchical linear models were proposed for the response variables following a normal distribution by Kim and Kang. In this article, we extend the hierarchical linear models to propose hierarchical generalized linear models (HGLMs) so that the response variables can follow the exponential family. We describe the details of the model when the response variable follows the Bernoulli distribution and the Poisson distribution. Simulation studies show that the empirical powers of the HGLM are greater than random effects model when region-level covariates are incorporated.

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

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. 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. 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. 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.

Inhalation vs Total Intravenous Anesthesia in Cancer Surgery: Where is the «Pendulum» Now? (Meta-Analysis and Review)

Comparative studies on the efficacy and safety of Inhalation Anesthesia (IA) and Total IntraVenous Anesthesia (TIVA) have been performed for many years, and the results were various. The aim of this study was to evaluate new data on the clinical efficacy of anesthetic preconditioning, the difference between inhalation and intravenous anesthesia on cardiac protection and clinically relevant outcomes in cancer surgery. Materials and methods . We carried out a systematic review and meta-analysis on searches and analysis of the literature over the past five years in accordance to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results. Out of the 759 articles which were initially identified, we selected 3 studies regarding the clinical significance of anesthetic cardioprotection and 10 studies comparing IA and TIVA in patients undergoing surgery for malignant diseases. Two meta-analyses and one multi-regional clinical trial (MRCT) suggest that further studies of the effectiveness of anesthetic cardioprotection is futile. A meta-analysis of 9 retrospective cohort studies and 1 MRCT showed a detrimental effect of IA on 3-year survival in surgical oncology (Hazard Ratio (HR): 1.73 (1.36; 1.96) Heterogeneity: Q = 8.336, df = 3, I 2 ; f 2 = 64.01, overall effect analysis: Z = 2.386 (P<0.017)). Analysis of 5-year mortality did not reveal any differences, although it did not remove any doubts about the possible negative effect of the use of IA in surgical oncology. Conclusion . Due to the futility of the previous efforts, the authors suggest not starting new studies aimed at finding evidence of the effectiveness of anesthetic cardioprotection on clinically relevant outcomes. However, since cohort studies indicate a possible beneficial effect of the use of TIVA in surgical oncology, the authors suggest conducting a serious comparative MRCT in this setting.

Methods for detecting outlying regions and influence diagnosis in multi-regional clinical trials

Due to the globalization of drug development, multi-regional clinical trials (MRCTs) have been increasingly adopted in clinical evaluations. In MRCTs, the primary objective is to demonstrate the efficacy of new drugs in all participating regions, but heterogeneity of various relevant factors across these regions can cause inconsistency of treatment effects. In particular, outlying regions with extreme profiles can influence the overall conclusions of these studies. In this article, we propose quantitative methods to detect these outlying regions and to assess their influences in MRCTs. The approaches are as follows: (1) a method using a dfbeta-like measure, a studentized residual obtained by a leave-one-out cross-validation (LOOCV) scheme; (2) a model-based significance testing method using a mean-shifted model; (3) a method using a relative change measure for the variance estimate of the overall effect estimator; and (4) a method using a relative change measure for the heterogeneity variance estimate in a random-effects model. Parametric bootstrap schemes are proposed to accurately assess the statistical significance and variabilities of the aforementioned influence diagnostic tools. We illustrate the effectiveness of these proposed methods via applications to two MRCTs, the RECORD and RENAAL studies.

Points to Consider for Implementation of the ICH E17 Guideline: Learning from Past Multiregional Clinical Trials in Japan.

We identified the major points that are described in the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) E17 guideline but have not been considered in the past multiregional clinical trials (MRCTs) used for drug approval in Japan to elucidate potential challenges in the implementation of the ICH E17 guideline in Japan. Based on the analysis of 167 MRCTs of 130 drugs, several points, such as the same dose setting and consistency between the overall and Japanese populations, in addition to good clinical practice compliance, have been well considered in ≥ 75% of MRCTs. In contrast, the use of relevant guidelines for disease and primary end point definitions, standardization of efficacy/safety information, sample size allocation, as well as training/validation on subject selection and primary end point, have been addressed less adequately and may need to be considered when planning future MRCTs. This study provides useful information for the implementation of the ICH E17 guideline in Japan.

Assessment of Overall Treatment Effect in the Presence of Inconsistent Regional Effects in Multiregional Clinical Trials

The use of multiregional clinical trials (MRCTs) in clinical developments increased to accelerate patients’ access to new drugs globally. MRCTs inherently assume that the treatment effect is consistent across regions; therefore, we generally estimate the overall treatment effect using a weighted mean of regional estimates with the proportions of enrolled patients as a weight. However, recent MRCTs occasionally encountered an inconsistency in treatment effect among regions. This study was motivated by two actual MRCTs showing the inconsistency of the treatment effects. In these trials, inconsistent treatment effects were observed in a few regions and the estimates in these regions impacted the overall treatment effect estimate. In this study, we propose an exploratory analysis to estimate the overall treatment effect based on robust estimation. The proposed estimator adaptively changes the weights for each region by minimizing the weighted jackknife-based mean squared error of the proposed estimator. We examined the utility of the proposed method through simulation studies. We found that the proposed estimators were less biased and more statistically powerful compared with other ordinary estimators when inconsistent regions existed. We also illustrated estimation of the overall treatment effect by applying the proposed estimators to the two MRCTs.

A Bayesian model for spatial partly interval-censored data

Partly interval-censored data often occur in cancer clinical trials and have been analyzed as right-censored data. Patients’ geographic information sometimes is also available and can be useful in testing treatment effects and predicting survivorship. We propose a Bayesian semiparametric method for analyzing partly interval-censored data with areal spatial information under the proportional hazards model. A simulation study is conducted to compare the performance of the proposed method with the main method currently available in the literature and the traditional Cox proportional hazards model for right-censored data. The method is illustrated through a leukemia survival data set and a dental health data set. The proposed method will be especially useful for analyzing progression-free survival in multi-regional cancer clinical trials.