Increased risk of hypocalcemia with decreased kidney function in patients prescribed bisphosphonates based on real-world data from the MID-NET® in Japan: a new-user cohort study.

BACKGROUND: In the post-marketing stage, cases of hypocalcemia associated with bisphosphonate preparations (BPs) have been reported in patients with decreased kidney function, despite warning against use of BPs in such patients in the package insert (PI) of Japan. The purpose of this study was to investigate the safety of BPs in patients with decreased kidney function. METHODS: The cohort study was conducted in patients with osteoporosis and newly prescribed bisphosphonate utilizing real-world data from MID-NET® in Japan. The adjusted hazard ratios (aHRs) for hypocalcemia (a corrected serum Ca level < 8.00 mg/dL) relative to the normal group were calculated in each decreased kidney function group (mild, moderate or severe group). RESULTS: A total of 14,551 patients were included in the analysis, comprising 2,601 (17.88%) with normal (eGFR ≥ 90 mL/min/1.73m2), 7,613 (52.32%) with mild (60 ≤ eGFR < 90 mL/min/1.73m2), 3,919 (26.93%) with moderate (30 ≤ eGFR < 60 mL/min/1.73m2), and 418 (2.87%) with severe kidney function (eGFR < 30 mL/min/1.73m2). The aHRs (95% confidence interval) for hypocalcemia were 1.85 (0.75-4.57), 2.30 (0.86-6.21), and 22.74 (8.37-61.78) in the mild, moderate, and severe groups, respectively. The increased risk of hypocalcemia depending on kidney function was also observed even when calculating the aHR for each specific BP such as alendronate sodium hydrate, minodronic acid hydrate, and sodium risedronate hydrate. Furthermore, similar results were obtained in the sensitivity analysis by altering the outcome definition to a 20% or more reduction in corrected serum Ca level from the baseline, as well as when focusing on patients with more than one laboratory test result per 30 days during the follow-up period. CONCLUSIONS: These findings suggest that the risk of hypocalcemia during BP prescription is higher in patients with decreased kidney function, particularly those with severely decreased kidney function. The quantitative real-world evidence on the safety risk of BPs obtained in this study has led to the PI revision describing a relationship between hypocalcemia risk and decreased kidney function as a regulatory action in Japan and will contribute to promoting the proper use of BPs with appropriate risk management in clinical practice.

Validity of identification algorithms combining diagnostic codes with other measures for acute ischemic stroke in MID-NET®.

PURPOSE: We aimed to develop a reliable identification algorithm combining diagnostic codes with several treatment factors for inpatients with acute ischemic stroke (AIS) to conduct pharmacoepidemiological studies using the administrative database MID-NET® in Japan. METHODS: We validated 11 identification algorithms based on 56 different diagnostic codes (International Classification of Diseases, Tenth Revision; ICD-10) using Diagnosis Procedure Combination (DPC) data combined with information on AIS therapeutic procedures added as "AND" condition or "OR" condition. The target population for this study was 366 randomly selected hospitalized patients with possible cases of AIS, defined as relevant ICD-10 codes and diagnostic imaging and prescription or surgical procedure, in three institutions between April 1, 2015 and March 31, 2017. We determined the positive predictive values (PPVs) of these identification algorithms based on comparisons with a gold standard consisting of chart reviews by experienced specialist physicians. Additionally, the sensitivities of them among 166 patients with the possible cases of AIS at a single institution were evaluated. RESULTS: The PPVs were 0.618 (95% confidence interval [CI]: 0.566-0.667) to 0.909 (95% CI: 0.708-0.989) and progressively increased with adding or limiting information on AIS therapeutic procedures as "AND" condition in the identification algorithms. The PPVs for identification algorithms based on diagnostic codes I63.x were >0.8. However, the sensitivities progressively decreased to a maximum of ~0.2 after adding information on AIS therapeutic procedures as "AND" condition. CONCLUSIONS: The identification algorithms based on the combination of appropriate ICD-10 diagnostic codes in DPC data and other AIS treatment factors may be useful to studies for AIS at a national level using MID-NET®.

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.

Cardiovascular risks associated with dipeptidyl peptidase-4 inhibitors monotherapy compared with other antidiabetes drugs in the Japanese population: A nationwide cohort study.

PURPOSE: We evaluated the cardiovascular risk associated with dipeptidyl peptidase-4 inhibitors (DPP-4Is) as monotherapy compared with other antidiabetic drugs in Japan. METHODS: We conducted a nationwide cohort study involving 2 716 000 diabetes patients in Japan. New users of any antidiabetic drug as monotherapy between 1 April 2010 and 31 October 2014 were identified. Occurrences of myocardial infarction (MI), heart failure (HF), and stroke requiring hospitalization associated with DPP-4Is were compared with those associated with biguanides (BGs), sulfonylureas (SUs), or α-glucosidase inhibitors (α-GIs). Adjusted hazard ratios (aHRs) for these outcomes were estimated by Cox proportional hazards model. Propensity score standardization was used to control for confounding. RESULTS: We identified 1 105 103 patients using DPP-4Is, 278 280 patients using BGs, 273 449 patients using SUs, and 217 026 patients using α-GIs. The risks of MI and HF for DPP-4I users were significantly higher than those for BG users (MI: aHR, 1.48 [95%CI, 1.20-1.82], HF: aHR, 1.46 [95%CI, 1.31-1.62]), while significantly lower than those for SU users (MI: aHR, 0.84 [95%CI, 0.72-0.98], HF: aHR, 0.86 [95%CI, 0.81-0.92]). The risk of MI for DPP-4I users was similar to that for α-GI users, while the risk of HF for DPP-4I users was slightly higher than for α-GI users (MI: aHR, 0.98 [95%CI, 0.82-1.17], HF: aHR, 1.12[95%CI, 1.04-1.21]). CONCLUSIONS: Risk of MI and HF requiring hospitalization associated with DPP-4Is as monotherapy was significantly higher than BGs, significantly lower than SUs, and similar to α-GIs.

Identification of gastrointestinal perforation based on ICD-10 code in a Japanese administrative medical information database and associated drug exposure risk factors.

PURPOSE: The purpose of this study is to evaluate the accuracy of gastrointestinal (GI) perforation ICD-10 coding in the Diagnosis Procedure Combination (DPC) database and to examine drug exposure risk factors for GI perforation. METHODS: A total of 100 patients with GI perforation ICD-10 codes were selected randomly from Kagawa University Hospital's DPC database between April 2011 and December 2016. Two experienced specialist physicians independently reviewed the medical records and classified cases as "definite A," "definite B," "probable," or "no GI perforation." The positive predictive values (PPVs) of "definite A/B" cases were calculated after stratification by sex, age, ICD-10 code, and diagnostic information in the DPC data. The number of prescribed drugs with side effects of GI perforation according to historical data was compared between "definite A/B" and "no GI perforation" cases. RESULTS: The overall PPV was 47.0% (95% confidence interval [CI], 36.9-57.2). However, the PPVs for the three categories of diagnostic information in the DPC data ("main diagnosis," "diagnosis causing admission," and "most resource-intensive diagnosis") were each more than 70% after excluding inappropriate patients. Additionally, the PPV focused on these three categories was 76.3% (95% CI, 59.8-88.6). Prescribed drugs with side effects of GI perforation were more frequently detected in "definite A/B" cases (P = .028). CONCLUSIONS: Although the overall PPV for GI perforation based on ICD-10 code was low, our results suggest that the PPV could be improved by appropriate selection of DPC diagnosis category and that use of multiple medications enhances the risk of GI perforation.

The utilization and challenges of Japan's MID-NET® medical information database network in postmarketing drug safety assessments: A summary of pilot pharmacoepidemiological studies.

PURPOSE: To examine the potential role of Medical Information Database Network (MID-NET® ), a newly established Japanese medical information database network, in postmarketing drug safety assessments through the characterization of its advantages and limitations in five pilot studies. METHODS: The pilot studies were designed to address three major objectives in postmarketing drug safety assessments, ie, the examination of actual drug utilization, the impact of safety-related regulatory actions, and drug-associated risks. The five studies were conducted on the following topics: (a) utilization of codeine-containing products and its relationship with respiratory depression, (b) impact of a Dear Healthcare Professional letter on hypocalcemia incidence associated with denosumab (Ranmark® ) use, (c) risk of acute myocardial infarction associated with antidiabetic drug use, (d) risk of glucose metabolism disorders associated with atypical antipsychotic drug use, and (e) prospective monitoring of abnormal laboratory test results during new drug prescriptions. RESULTS: The pilot studies were successfully conducted and demonstrated the value of MID-NET® in postmarketing drug safety assessments. In particular, the ability to utilize laboratory test results as objective clinical indicators is a major advantage of this database. Potential limitations include a relatively small sample size and a lack of patient-level data linkages among hospitals. CONCLUSIONS: MID-NET® was confirmed to be a valuable database for postmarketing drug safety assessments. The use of laboratory test results to define clinical outcomes may allow more objective and accurate analyses to be conducted. These studies furthered our understanding of the characteristics of MID-NET® , including its advantages and limitations.

Establishment of the MID-NET® medical information database network as a reliable and valuable database for drug safety assessments in Japan.

PURPOSE: To establish a new medical information database network (designated MID-NET® ) to provide real-world data for drug safety assessments in Japan. METHODS: This network was designed and developed by the Ministry of Health, Labour and Welfare and the Pharmaceuticals and Medical Devices Agency in collaboration with 23 hospitals from 10 healthcare organizations across Japan. MID-NET® is a distributed and closed network system that connects all collaborative organizations through a central data center. A wide variety of data are available for analyses, including clinical and administrative information. Several coding standards are used to standardize the data stored in MID-NET® to allow the integration of information originating from different hospitals. A rigorous and consistent quality management system was implemented to ensure that MID-NET® data are of high quality and meet Japanese regulatory standards (good post-marketing study practice and related guidelines). RESULTS: MID-NET® was successfully established as a reliable and valuable medical information database and was officially launched in April 2018. High data quality with almost 100% consistency was confirmed between original data in hospitals and the data stored in MID-NET® . A major advantage is that approximately 260 clinical laboratory test results are available for analysis. CONCLUSIONS: MID-NET® is expected to be a major data source for drug safety assessments in Japan. Experiences and best practices established in MID-NET® may provide a model for the future development of similar database networks.

Absence of ethnic differences in the pharmacokinetics of moxifloxacin, simvastatin, and meloxicam among three East Asian populations and Caucasians.

AIM: To examine whether strict control of clinical trial conditions could reduce apparent differences of pharmacokinetic (PK) parameters among ethnic groups. METHODS: Open-label, single dose PK studies of moxifloxacin, simvastatin and meloxicam were conducted in healthy male subjects from three East Asian populations (Japanese, Chinese and Koreans) and one Caucasian population as a control. These three drugs were selected because differences in PK parameters have been reported, even though the backgrounds of these East Asian populations are similar. Moxifloxacin (400 mg) was administered orally to 20 subjects, and plasma and urine levels of moxifloxacin and its metabolite (M2) were measured. Simvastatin (20 mg) was given to 40 subjects, and plasma levels of simvastatin and simvastatin acid were measured. Meloxicam (7.5 mg) was given to 30 subjects and its plasma concentration was determined. Intrinsic factors (polymorphism of UGT1A1 for moxifloxacin, SLCO1B1 for simvastatin, and CYP2C9 for meloxicam) were also examined. RESULTS: AUCinf values for moxifloxacin, simvastatin and meloxicam showed no significant differences among the East Asian groups. Cmax values of moxifloxacin and simvastatin, but not meloxicam, showed significant differences. There were no significant differences of data for M2 or simvastatin acid. Genetic analysis identified significant differences in the frequencies of relevant polymorphisms, but these differences did not affect the PK parameters observed. CONCLUSIONS: Although there were some differences in PK parameters among the three East Asian groups, the present study performed under strictly controlled conditions did not reproduce the major ethnic differences observed in previous studies.

Different Development Strategies Affecting Japan's Drug lag between Japan-Based and Foreign-Based Companies.

We examined the development strategies of new molecular entities approved during a 10-year period (fiscal years of 2012-2021) in Japan to determine the differences in drug lag between Japan and foreign companies. The results demonstrated a clear difference in development strategies. For example, products were usually developed through a "only-Japan" strategy by Japan companies (51.1% of products), compared to a "MRCT (multi-regional clinical trials)" strategy by foreign companies (54.9% of products). Regarding types of licenses, for Japan companies, the percentage of original products was higher in the category of less drug lag, such as "no approval in the US and EU" (59.1%), whereas the percentage of "license-in" products was markedly higher in the "drug lag ≥ 5 years" category (52.5%). Such differences were not observed for products developed by foreign companies. Of 64 license-in products developed by Japan companies with a drug lag > 5 years, 51 (79.7%) had already been approved in the US or EU at initiation of clinical development in Japan. The origin of approximately half (34) of the products was from the emerging companies (non-member foreign companies of the Japan Pharmaceutical Manufacture Association). These results suggest that more global cooperation of Japan companies, particularly with emerging foreign companies, is necessary in terms of the earlier timing of license-in and development strategies of products to promote drug development without drug lag or drug loss in Japan.

Real-world prescription of anti-COVID-19 drugs in hospitalized patients with COVID-19 in Japan.

OBJECTIVE: Prescription trends and patterns of anti-COVID-19 drugs in hospitalized patients were examined based on real world data to understand the use of anti-COVID-19 drugs in clinical practice in Japan. DESIGN: The longitudinal and cross-sectional study was conducted utilizing data from January 1, 2019 to December 31, 2021 of the MID-NET® medical information database, which stored the electronic medical records, administrative claim data, and diagnosis procedure combination data of patients in Japan. PARTICIPANTS: Hospitalized patients with a COVID-19-related diagnosis who received at least one anti-COVID-19 drug between April 1, 2020 and December 31, 2021. EXPOSURES: The following 14 drugs were included in this study: remdesivir, baricitinib, combination product of casirivimab and imdevimab, favipiravir, dexamethasone, ivermectin, azithromycin, nafamostat mesylate, camostat mesylate, ciclesonide, tocilizumab, sarilumab, combination product of lopinavir and ritonavir, and hydroxychloroquine. RESULTS: We identified 5,717 patients hospitalized with COVID-19 and prescribed at least one anti-COVID-19 drug. The entire cohort generally included patients over 41-50 years and more males. The most common prescription pattern was dexamethasone monotherapy (22.9%), followed by the concomitant use of remdesivir and dexamethasone (15.0%), azithromycin monotherapy (15.0%), remdesivir monotherapy (10.2%), and nafamostat mesylate monotherapy (8.5%). However, an often prescribed anti-COVID-19 drug differed depending on the period. CONCLUSIONS AND RELEVANCE: This study revealed the real-world situation of anti-COVID-19 drug prescriptions in hospitalized COVID-19 patients in Japan. A prescribed drug would depend on the latest scientific evidence, such as efficacy, safety, and approval status, at the time of prescription. Understanding the prescription of anti-COVID-19 drugs will be important for providing the most up-to-date treatments to patients and evaluating the benefit and/or risk of anti-COVID-19 drugs based on the utilization of an electronic medical record database.

Simultaneous Global Drug Development and Multiregional Clinical Trials (MRCT): 5 Years After Implementation of ICH E17 Guidelines.

The ICH E17 guidelines (2014-2017) on Multiregional Clinical Trials (MRCT) was a joint effort by the regulators and industry to facilitate simultaneous global drug development and registration through taking a strategic approach for clinical trials. In other words, the objective was to reduce the time it takes to bringing medications to patients around the world through minimizing unnecessary duplication of local or regional studies, which may add the regulatory burden to cost and time of bringing new therapies to patients. Under the auspices of ICH, training materials were created and provided to various stakeholders. Despite the successful promotion of the benefits of ICH E17 MRCT guidelines across the different regions, the uptake of some concepts (e.g., pooling strategy) in the ICH E17 guidelines has been slow. This paper describes various factors which could affect the conduct of MRCT at a global level, including ambiguity in definition of "region" (in MRCT), new regulatory requirements to enroll a diverse patient population, the use of decentralized clinical trials, use of data sources other than randomized clinical trials (e.g., use of Real Word Data), and the impact of the COVID-19 pandemic on the conduct of MRCT.

Risk of neutropenia in psoriasis patients prescribed anti-IL-23 antibody in comparison with anti-IL-17 antibody or adalimumab based on real-world data from the MID-NET® in Japan.

BACKGROUND: To evaluate the risk of neutropenia during treatment with anti-IL-23 antibodies in patients with psoriasis. METHOD: We conducted an observational study with cohort design using MID-NET® in Japan. We identified patients with psoriasis who were newly prescribed anti-IL-23 antibodies, anti-IL-17-antibodies, adalimumab, or apremilast between January 1, 2009, and March 31, 2021. We estimated the adjusted hazard ratio (aHR) of anti-IL-23 antibodies compared to that of anti-IL-17 antibodies, adalimumab, or apremilast, for the risk of grade 2 (neutrophil count < 1,500/µL) or grade 3 (neutrophil count < 1,000/µL) neutropenia. RESULTS: Overall, 287 patients on anti-IL-23 antibodies, 189 patients on anti-IL-17 antibodies, 293 patients on adalimumab, and 540 patients on apremilast were included. Compared with anti-IL-17 antibodies, the aHR (95% confidence interval (CI)) of anti-IL-23 antibodies was 0.83 (0.27-2.51) for grade 2 and 0.40 (0.02-7.60) for grade 3 neutropenia; that when compared with adalimumab was 0.76 (0.28-2.06) for grade 2 but was not calculated for grade 3 as no cases were found; and that compared with apremilast was 3.88 (0.62-24.48) for grade 2 and 0.43 (0.02-11.63) for grade 3 neutropenia. CONCLUSION: No clear increase in the risk of neutropenia with anti-IL-23 antibodies was observed.

Detection Algorithms for Gastrointestinal Perforation Cases in the Medical Information Database Network (MID-NET®) in Japan.

BACKGROUND: The Medical Information Database Network (MID-NET®) in Japan is a vast repository providing an essential pharmacovigilance tool. Gastrointestinal perforation (GIP) is a critical adverse drug event, yet no well-established GIP identification algorithm exists in MID-NET®. METHODS: This study evaluated 12 identification algorithms by combining ICD-10 codes with GIP therapeutic procedures. Two sites contributed 200 inpatients with GIP-suggestive ICD-10 codes (100 inpatients each), while a third site contributed 165 inpatients with GIP-suggestive ICD-10 codes and antimicrobial prescriptions. The positive predictive values (PPVs) of the algorithms were determined, and the relative sensitivity (rSn) among the 165 inpatients at the third institution was evaluated. RESULTS: A trade-off between PPV and rSn was observed. For instance, ICD-10 code-based definitions yielded PPVs of 59.5%, whereas ICD-10 codes with CT scan and antimicrobial information gave PPVs of 56.0% and an rSn of 97.0%, and ICD-10 codes with CT scan and antimicrobial information as well as three types of operation codes produced PPVs of 84.2% and an rSn of 24.2%. The same algorithms produced statistically significant differences in PPVs among the three institutions. Combining diagnostic and procedure codes improved the PPVs. The algorithm combining ICD-10 codes with CT scan and antimicrobial information and 80 different operation codes offered the optimal balance (PPV: 61.6%, rSn: 92.4%). CONCLUSION: This study developed valuable GIP identification algorithms for MID-NET®, revealing the trade-offs between accuracy and sensitivity. The algorithm with the most reasonable balance was determined. These findings enhance pharmacovigilance efforts and facilitate further research to optimize adverse event detection algorithms.

Lower Risks of Gastrointestinal Perforation and Intestinal Obstruction in Patients with Atypical Antipsychotics in Comparison with Typical Antipsychotics Based on Real-World Data from the MID-NET® in Japan.

Intestinal perforation and obstruction are known to be one of the adverse events caused by antipsychotics; however, warning information on package inserts varies among antipsychotics. To investigate the risks of gastrointestinal perforation and intestinal obstruction in patients prescribed atypical antipsychotics compared with those in patients prescribed typical antipsychotics, a nested case-control study was conducted utilizing real-world data from the MID-NET® medical information database in Japan. The study period spanned from January 1, 2009, to December 31, 2018. We found that the risks of gastrointestinal perforation and intestinal obstruction in patients prescribed atypical antipsychotics were significantly lower than those in patients prescribed typical antipsychotics (adjusted odds ratio, 0.48; 95% confidence interval, 0.29-0.80). This finding was supported with prolonged periods for the exposure definition in the sensitivity analyses. In addition, no major differences in the risks of atypical antipsychotics, such as risperidone, quetiapine, olanzapine, and aripiprazole, were identified in this study. The safety profile regarding the lower risks of gastrointestinal perforation and intestinal obstruction in patients prescribed atypical antipsychotics should be considered when choosing antipsychotics in clinical practice in terms of the proper use of such drugs.

Characteristics of pharmacogenomics/biomarker-guided clinical trials for regulatory approval of anti-cancer drugs in Japan.

Pharmacogenomics (PGx) or biomarker (BM) has the potential to facilitate the development of safer and more effective drugs in terms of their benefit/risk profiles by stratifying population into categories such as responders/non-responders and high-/low-risks to drug-induced serious adverse reactions. In the past decade, practical use of PGx or BM has advanced the field of anti-cancer drug development. To identify the characteristics of the PGx/BM-guided clinical trials for regulatory approval of anti-cancer drugs in Japan, we collected information on design features of 'key trials' in the review reports of anti-cancer drugs that were approved after the implementation of the 'Revised Guideline for the Clinical Evaluation of Anti-cancer drugs' in April 2006. On the basis of the information available on the regulatory review data for the newly approved anti-cancer drugs in Japan, this article aims to explain the limitations and points to consider in the study design of PGx/BM-guided clinical trials.

Descriptive Analysis for the Trend of Pharmacovigilance Planning in Risk Management Plans on New Drugs Approved During 2016-2019.

BACKGROUND: Japanese pharmaceutical authorities have conducted regulatory renovations of pharmacovigilance planning (PVP) since implementing new procedures for developing post-marketing study plans in 2018 in order to promote more focused and scientific approaches. This study aimed to descriptively assess the effects of those regulatory renovations on PVP for new drugs in Japan. METHODS: We identified PVP information (drug characteristics, efficacy and safety issues, and additional activities) from the first version of risk management plans for new drugs approved between 2016 and 2019. The following indicators were analyzed: (1) proportion of the number of drugs with at least one efficacy issue among all the drugs, (2) proportion of the number of safety issues with additional activity among all the safety issues, and (3) proportion of database studies among all additional activities. RESULTS: In total, 168 drugs, 1212 safety issues, and 301 additional activities were identified. The proportion of drugs with at least one efficacy issue decreased from 91.4% in 2016 to 27.3% in 2019, and the proportion of safety issues with additional activity also decreased from 93.9% in 2016 to 53.7% in 2019. In contrast, the proportion of database studies increased from 0 to 19.2%. The percentages of additional activities targeting important identified and potential risks also gradually decreased during the 4-year period. CONCLUSION: Notable changes in the three indicators during 2016-2019 were observed, which suggests that regulatory renovation has affected PVP in Japan.

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.

Characterizing Granulocytopenia Associated with Thiamazole in Patients with Hyperthyroidism Based on Real-World Data from the MID-NET in Japan.

Despite the requirement of routine blood tests during thiamazole treatment in Japan, granulocytopenia among patients treated with thiamazole has been occasionally reported to the Pharmaceuticals and Medical Devices Agency (PMDA). To characterize granulocytopenia in patients with thiamazole in Japan, the effects of routine blood tests were examined in a cohort of new users of thiamazole or propylthiouracil utilizing the MID-NET. The occurrence of granulocytopenia (neutrophil count ≤ 1,500/µL) in a given period was compared between patients with and without blood test results prior to the period. The trend in neutrophil count during thiamazole treatment was also compared between patients with and without granulocytopenia. A nested case-control study based on the cohort was conducted to identify potential risk factors for granulocytopenia during thiamazole treatment. In the new user cohort including 4,371 patients treated with thiamazole, the occurrence of granulocytopenia in patients who had undergone blood tests at all previous periods was similar or higher than that among those who had not undergone blood test in all previous periods (e.g., adjusted odds ratio in period 2 was 1.63). The neutrophil count was relatively lower in the group of patients with granulocytopenia even before the occurrence of granulocytopenia. In a nested case-control study, an upward tendency of the risk was observed when a patient was co-prescribed anti-arrhythmic drugs or antiulcer drugs with thiamazole. The characteristics of granulocytopenia during thiamazole treatment elucidated in this study should be recognized in clinical practice for the proper use of thiamazole.

Cardiovascular risk of urate-lowering drugs: A study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

In the present study, we aimed to investigate the association between urate-lowering drugs and cardiovascular events, primarily focusing on the risk of febuxostat and topiroxostat when compared with allopurinol in Japan. We conducted an observational study with a cohort design using the National Database of Health Insurance Claims and Specific Health Checkups of Japan, including new urate-lowering drugs users between August 1, 2010, and March 31, 2018. Exposure and control groups were defined based on the first prescription of urate-lowering drugs as follows: febuxostat or topiroxostat for exposure groups, allopurinol for the control group, and benzbromarone for the secondary control group. The primary outcome was cardiovascular events, defined as a composite of acute coronary syndrome, cerebral infarction, and cerebral hemorrhage. Hazard ratios were estimated using a Cox proportional hazards model. The number of patients in each exposure and control group was 1,357,671 in the febuxostat group, 83,683 in the topiroxostat group, 1,273,211 in the allopurinol group, and 258,786 in the benzbromarone group. The adjusted hazard ratios for the cardiovascular risk were 0.97 (95% confidence interval [CI]: 0.95-0.98) for febuxostat and 0.84 (95% CI: 0.78-0.90) for topiroxostat groups. The benzbromarone group exhibited similar results. No increased cardiovascular risk was observed with febuxostat or topiroxostat when compared with allopurinol in patients with hyperuricemia in Japan. These results provide real-world evidence regarding the cardiovascular risk associated with urate-lowering drugs, indicating that no additional safety-related regulatory actions are warranted in Japan.

Use of National Database of Health Insurance Claims and Specific Health Checkups for examining practical utilization and safety signal of a drug to support regulatory assessment on postmarketing drug safety in Japan.

The Pharmaceuticals and Medical Devices Agency (PMDA) has conducted many pharmacoepidemiological studies for postmarketing drug safety assessments based on real-world data from medical information databases. One of these databases is the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), containing health insurance claims of almost all Japanese individuals (over 100 million) since April 2009. This article describes the PMDA's regulatory experiences in utilizing the NDB for postmarketing drug safety assessment, especially focusing on the recent cases of use of the NDB to examine the practical utilization and safety signal of a drug. The studies helped support regulatory decision-making for postmarketing drug safety, such as considering a revision of prescribing information of a drug, confirming the appropriateness of safety measures, and checking safety signals in real-world situations. Different characteristics between the NDB and the MID-NET® (another database in Japan) were also discussed for appropriate selection of data source for drug safety assessment. Accumulated experiences of pharmacoepidemiological studies based on real-world data for postmarketing drug safety assessment will contribute to evolving regulatory decision-making based on real-world data in Japan.