Development of a clinical prediction model for recurrence and mortality outcomes after Clostridioides difficile infection using a machine learning approach.

OBJECTIVES: Clostridioides difficile infection (CDI) is associated with a large burden of morbidity and mortality worldwide. Previous studies have developed models for predicting recurrence and mortality following CDI, but no machine learning predictive models have been developed specifically using data from Japanese patients. METHODS: Using a database of records from acute care hospitals in Japan, we extracted records from January 2012 to September 2016 (plus a 60-day lookback window). A total of 19,159 patients were included. We used a machine learning approach, XGBoost, and compared it to a traditional unregularized logistic regression model. The first 80% of the dataset (by patient index date) was used to optimize model hyperparameters and train the final models, and evaluation was performed on the remaining 20%. We measured model performance by the area under the receiver operator curve and assessed feature importance using Shapley additive explanations. RESULTS: Performance was similar between the machine learning approach and the classical logistic regression model. Logistic regression performed slightly better than XGBoost for predicting mortality. CONCLUSION: XGBoost performed slightly better than logistic regression for predicting recurrence, but it was not competitive with existing published models. Despite this, a future machine learning-based application provided in a bedside setting at low cost might be a clinically useful tool.

Medication Adherence/Persistence and Demographics of Japanese Dyslipidemia Patients on Statin-Ezetimibe as a Separate Pill Combination Lipid-Lowering Therapy　- An Observational Pharmacy Claims Database Study.

BACKGROUND: This study aimed to identify potential predictors of medication adherence and persistence with statin-ezetimibe combinational lipid-lowering therapy (LLT) as a separate pill combination in a real-world setting in Japan.Methods and Results:Patients newly switched to statin-ezetimibe combinational LLT from statin monotherapy were identified within a Japanese national pharmacy claims database during January 2015 to April 2018. Adherence and persistence were measured by the proportion of days covered (PDC), time to treatment discontinuation and persistence rate at 1 year. A stepwise multivariate logistic regression model and Cox proportional hazards regression model were used to explore potential predictors associated with adherence and persistence, respectively. Among 6,921 patients, 71.9% were adherent (PDC ≥80%), and 83.6% were persistent at 1 year after initiation. Patients aged ≤54 years and ≥75 years were prone to be more non-adherent. Secondary prevention was associated with better adherence and longer persistence. Concomitant use of medications for depression/anxiety was associated with shorter persistence, whereas use of antihypertensive drugs was associated with better adherence and persistence. CONCLUSIONS: Age, concomitant use of certain classes of medications (or the existence of these diseases) and secondary prevention were associated with adherence and persistence of statin-ezetimibe combinational LLT. Given that dyslipidemia is a chronic disease requiring life-long control, active interventions are required for patients with poor adherence and persistence.

The efficacy and safety of tazobactam/ceftolozane in Japanese patients with uncomplicated pyelonephritis and complicated urinary tract infection.

We report efficacy and safety results for a combination of a novel cephalosporin class antibiotic and a ß-Lactamase inhibitor, tazobactam/ceftolozane (1:2) at a dose of 1.5 g intravenously every 8 h in Japanese patients with uncomplicated pyelonephritis and complicated urinary tract infection. This study design was a nonrandomized, multicenter, open-label trial, and the treatment period was 7 days. Of 115 patients enrolled in this study, 114 received tazobactam/ceftolozane, and 90 were included in the efficacy analyses. Ninety-nine isolates (bacterial count ≥105 CFU/mL) were identified by urine culture. The main baseline uropathogens were Escherichia coli (80 isolates), Klebsiella pneumoniae (8 isolates), and Proteus mirabilis (3 isolates). Of these, 13 isolates were ESBL-producers. The favorable per-patient microbiological response rate at 7 days after the final administration of tazobactam/ceftolozane was 80.7% (71/88). The response rate in uncomplicated pyelonephritis was 90.0% (36/40), complicated pyelonephritis 63.6% (14/22), and complicated cystitis 80.8% (21/26). The favorable clinical response rate was 96.6% (86/89), and composite response rate (based on microbiological and clinical response) was 80.7% (71/88). The eradication rate by uropathogen was 83.5% (66/79) in E. coli, 42.9% (3/7) in K. pneumoniae, and 100% (3/3) in P. mirabilis. The incidence of drug-related adverse events was 17.5% (20/114 patients). The most common drug-related adverse events were diarrhea and alanine aminotransferase increased in 5.3% (6/114 patients each). Drug-related serious adverse events and deaths were not observed. These results support the safety and efficacy of tazobactam/ceftolozane and suggest it will be a useful treatment for uncomplicated pyelonephritis and complicated urinary tract infection.

The efficacy and safety of tazobactam/ceftolozane in combination with metronidazole in Japanese patients with complicated intra-abdominal infections.

Tazobactam/ceftolozane, a novel antimicrobial therapy, is active against Pseudomonas aeruginosa and most extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae. We report the results of the efficacy and safety of tazobactam/ceftolozane in Japanese patients with complicated intra-abdominal infections (cIAI). A multicenter, open-label, noncomparative study (MK-7625A Protocol 013, ClinicalTrials.gov Identifier: NCT02739997) to investigate the efficacy and safety of tazobactam/ceftolozane used in combination with metronidazole in Japanese patients with cIAI was conducted. One hundred Japanese patients with cIAI received tazobactam/ceftolozane 1.5 g (tazobactam 0.5 g/ceftolozane 1 g) plus metronidazole 500 mg intravenously every 8 h for 60 min for 4-14 days. The clinical response rate at the Test-of-Cure visit (TOC; Day 28 ± 2 days) was 92.0% (81/88 subjects). By disease type, the clinical response rates were 92.3% (24/26) for cholecystitis, 100% (6/6) for liver abscess, 93.5% (58/62) for intra-abdominal abscess and 90.2% (55/61) for peritonitis. The per-subject microbiological response rate at the TOC was 90.2% (55/61). Per-pathogen microbiological response rates in the most common baseline pathogens were Escherichia coli 90.2% (37/41), Kebsiella pneumoniae 91.7% (11/12), Streptococcus anginosus 100% (11/11), Streptococcus constellatus 90.0% (9/10) and Bacteroides fragilis 95.2% (20/21). The most common drug-related AEs were aspartate aminotransferase increased (11.0%) and alanine aminotransferase increased (9.0%). No serious drug-related AE was reported during the study. The favorable effect of tazobactam/ceftolozane in the treatment of cIAI suggests that the agent will be useful in clinical practice in Japan.

Comorbidities and co-medications in populations with and without chronic hepatitis C virus infection in Japan between 2015 and 2016.

BACKGROUND: Direct-acting anti-viral agents have improved the treatment of chronic hepatitis C virus (HCV) infection, but this treatment is challenging for patients using co-medications because of potential drug-drug interactions. This study aimed to examine the comorbidities and co-medications of Japanese chronic HCV patients by age group, compared with a non-HCV patient population. METHODS: This was a retrospective observational study using a hospital-based medical claims database. We extracted data of patients with chronic HCV aged ≥18 years, and age-, sex-, and hospital-matched patients without HCV, for the period from January 2015 to November 2016, and then examined chronic comorbidities, long-term co-medications, and medications prescribed at least once during the study period. RESULTS: We analysed data from 128,967 chronic HCV patients and 515,868 non-HCV patients. The median age was 70 years, and 51.0% of patients were male. More chronic HCV patients than non-HCV patients (70.5% vs. 47.1%) had at least one comorbidity, and older patients had more comorbidities than younger patients. The most common comorbidities in chronic HCV patients were diseases of oesophagus, stomach and duodenum (41.7%), followed by hypertensive diseases (31.4%). Chronic HCV patients used co-medications more commonly than non-HCV patients, and older patients used more co-medications. The most common long-term co-medications in chronic HCV patients were proton pump inhibitors (14.0%), which were prescribed to 31.9% of chronic HCV patients at least once during the study period. CONCLUSIONS: Patients with chronic HCV in Japan had more comorbidities than patients without chronic HCV regardless of age. Particularly older patients, who constitute the majority of the HCV patient population in Japan, commonly had multiple comorbidities and used co-medications. To optimise HCV treatment, physicians need to know the exact medication profiles of patients and take appropriate action to manage drug-drug interactions.

The effect of bezlotoxumab for prevention of recurrent Clostridium difficile infection (CDI) in Japanese patients.

Recurrent Clostridium difficile infection is considered as a significant health care burden. The global study (MODIFY II) of antibody treatment (bezlotoxumab) for the prevention of recurrent C. difficile infection includes Japanese patients (95 subjects); The aim of this subgroup analysis is to report the data obtained from Japanese patients. Patients with C. difficile infection receiving standard of care antibiotic treatment and a single infusion of bezlotoxumab 10 mg/kg, actoxumab 10 mg/kg + bezlotoxumab 10 mg/kg or placebo. Recurrent C. difficile infection through Week 12 was evaluated. In the Full Analysis Set (93 subjects), 91% were older than 65 years of age and 93% were hospitalized at the time of study entry. The standard of care antibiotic for C. difficile infection was metronidazole for 57 subjects and vancomycin for 36 subjects. The recurrent C. difficile infection rate was 46% in the placebo, 21% in the bezlotoxumab (p = 0.0197) and 28% in the actoxumab + bezlotoxumab group. No additive recurrent C. difficile infection-reducing effect with the addition of actoxumab was demonstrated. There were no events representing safety concern in bezlotoxumab. Among 54 clinical isolates of C. difficile as a baseline culture in Japanese patients, the common ribotypes were 052 (28%), 018 (19%), 002 (15%) and 369 (9%). It showed distinctly different distribution from that in the United States and Europe. The superior effect of bezlotoxumab 10 mg/kg in the prevention of recurrent C. difficile infection suggests that the agent will be useful in the rapidly aging Japanese society.

Vaniprevir plus peginterferon alfa-2b and ribavirin in treatment-experienced Japanese patients with hepatitis C virus genotype 1 (GT1b) infection: Phase 3 studies.

BACKGROUND AND AIM: Vaniprevir is a macrocyclic hepatitis C virus (HCV) non-structural (NS)3/4A protease inhibitor. The objective of these phase 3 multicenter, open-label trials was to evaluate the safety and efficacy of vaniprevir + peginterferon alfa-2b + ribavirin (PR) in Japanese patients with HCV genotype (GT)1 infection who had previously failed treatment with interferon-based regimens. METHODS: Japanese patients with chronic HCV GT1 were enrolled. In PN044, patients with previous relapse or virologic breakthrough were randomized to vaniprevir (300 mg twice daily) + PR for 12 weeks followed by PR for another 12 weeks (12-week arm) or vaniprevir + PR for 24 weeks (24-week arm). In PN045, patients with previous partial/null response received vaniprevir + PR for 24 weeks. The primary endpoint was sustained virologic response at 24 weeks after completing treatment (SVR24 ). RESULTS: In PN044 (n = 51), SVR24 was 92.0% and 96.2% in the 12- and 24-week arms, respectively. In PN045 (n = 42), SVR24 was 61.9% in all patients and 55.2% in previous null responders. In both studies, vaniprevir + PR was generally safe and well tolerated; the majority of adverse events were mild/moderate and included pyrexia, decreased hemoglobin, headache, nausea, pruritus, and decreased platelet count. Polymorphisms in the HCV NS3 gene at baseline (Y56, Q80, and V170) did not impact treatment outcome. Virologic failure was principally associated with the on-treatment emergence of R155 or D168 mutations. CONCLUSIONS: Vaniprevir + PR is an effective, well-tolerated treatment for Japanese patients with HCV GT1 infection who failed previous interferon-based treatment. ClinicalTrials.gov Identifier NCT01405937 and NCT01405560 (Protocols PN044 and PN045).

Clinicopathological features of PD-L1 protein expression, EBV positivity, and MSI status in patients with advanced gastric and esophagogastric junction adenocarcinoma in Japan.

This real-world study examined the prevalence of programmed death ligand-1 (PD-L1) expression and assessed the frequency of microsatellite instability-high (MSI-H) status and Epstein-Barr virus (EBV) positivity in Japanese patients with advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma. This multicenter (5 sites), retrospective, observational study (November 2018-March 2019) evaluated Japanese patients with advanced gastric and GEJ adenocarcinoma after surgical resection (Stage II/III at initial diagnosis) or unresectable advanced cancer (Stage IV). The primary objectives were prevalence of PD-L1 expression (combined positive score [CPS] ≥1), MSI status, and EBV positivity. Tumor specimens of 389/391 patients were analyzed (male, 67.1%; mean age, 67.6 ± 12.2 years); 241/389 (62%) were PD-L1 positive, 24/379 (6.3%) had MSI-H tumors, and 13/389 (3.3%) were EBV positive. PD-L1 expression was higher in tumor-infiltrating immune cells than in tumor cells for lower CPS cutoffs. Among patients with MSI-H tumors and EBV-positive tumors, 19/24 (79.2%) and 9/13 (69.2%), respectively, were PD-L1 positive. A greater proportion of patients with MSI-H tumors (83.3% [20/24]) were PD-L1 positive than those with MSI-low/stable tumors (60.8% [216/355]; p = .0297); similarly, an association was observed between history of H pylori infection and PD-L1 expression. A higher proportion of patients with MSI-H tumors demonstrated PD-L1 expression with a CPS ≥10 (66.7% [16/24]) vs those with MSI-low/stable tumors (24.8% [88/355]; p < .0001). The prevalence of PD-L1 positivity among Japanese patients was comparable to that in previous pembrolizumab clinical trials and studies in gastric cancer. Particularly, higher PD-L1 expression was observed in MSI-H tumors.

Healthcare resource utilization and economic burden of antifungal management in patients with hematologic malignancy in Japan: a retrospective database study.

OBJECTIVE: To examine treatment patterns of real-world antifungal management of patients at high risk of invasive fungal infections (IFI) and evaluate healthcare resource utilization and costs associated with antifungal management of IFIs in Japan. METHODS: This retrospective, observational study extracted data from a hospital-based claims database for patients in Japan who either (a) underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), or (b) were hospitalized with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) and received chemotherapy during the study period of January 2010 to January 2019. RESULTS: 863 patients were included in the allo-HSCT cohort and 4498 patients were included in the AML/MDS cohort. In the allo-HSCT cohort, 91% received more than one antifungal drug during the index hospitalization. In the AML/MDS cohort, approximately 50% received more than one antifungal drug during the index hospitalization. For both the allo-HSCT and AML/MDS cohorts, about 90% of the total cost was attributed to inpatient costs. Of note, both the total cost (the total inpatient and outpatient cost) and the index hospitalization costs were higher in patients treated with multiple antifungal drugs than in those treated with a single antifungal drug during the index hospitalization. Despite being at high IFI risk, 12% of the patients in the AML/MDS cohort did not receive antifungal drugs during the index hospitalization. CONCLUSIONS: Most patients with hematologic malignancy and high IFI risk underwent complicated antifungal management requiring use of multiple drugs, and accounted for high healthcare resource utilization and costs.

The disease burden of mucormycosis in Japan: results from a systematic literature review and retrospective database study.

OBJECTIVE: To evaluate outcomes, healthcare resource utilization, and costs associated with mucormycosis in inpatient settings in Japan. METHODS: We performed a systematic literature review, followed by a retrospective database study using hospital health claims for patients in Japan hospitalized with a diagnosis of mucormycosis between January 2010 and January 2019. Outcomes assessed included duration of index hospitalization; index stay mortality; hospital readmission within 30, 60, and 90 days after index hospitalization discharge; drug/treatment utilization and patterns; number of patients examined for mucormycosis during the index hospitalization; and index stay inpatient costs. RESULTS: From our systematic literature review of articles describing 133 patients with mucormycosis, mortality in the index hospitalization was 55.6%. From our database study of 126 patients hospitalized for mucormycosis, mortality during the index hospitalization was 35.7% and mean index stay duration was 94 days. Hematologic malignancies were the most common risk factor in the literature review and the most common comorbidity in the database study. During the index stay, 39 patients (31.0%) received liposomal amphotericin B (L-AMB) treatment and 74 patients (58.7%) received other antifungal treatments. Median total inpatient costs for the index hospitalization were equivalent to approximately US$60,945, including US$29,283 in drug costs. CONCLUSIONS: This study investigated the healthcare resource utilization and cost of medical resources caused by mucormycosis in Japan. The drug costs for antifungal treatments comprised about half of total inpatient costs. Mucormycosis leads to high mortality, high healthcare resource utilization, and high costs.

The clinical and economic burden of cytomegalovirus management post allogeneic hematopoietic stem cell transplantation in Japan - a retrospective database study.

Introduction: Reactivation of cytomegalovirus (CMV) infection is a major threat and it causes significant morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). There remains, however, a paucity of evidence regarding the economic burden of current CMV management in Japan. The aim of this study is to characterize the healthcare resource utilization (HCRU) and cost incurred for CMV management post allo-HSCT, using a Japanese hospital claims database.Methods: Patients who underwent allo-HSCT between April 2010 and March 2018 were identified and followed up for 180 days.Results: In total, 916 patients were included for analysis and categorized into CMV (-) group and CMV (+) group based on the presence of a CMV episode within 100 days post allo-HSCT. A CMV episode was defined as evidence of receiving at least one dose of the following anti-CMV drugs, ganciclovir, foscarnet, or valganciclovir. The mean (± standard deviation [SD]) total length of stay was 93.6 (± 43.7) days in the CMV (+) group, which was significantly longer than 55.9 (±40.6) days in the CMV (-) group, and this trend was more pronounced in patients with multiple CMV episodes. The mean (±SD) total medical cost within 180 days post allo-HSCT was US$122,328 (±56,977) in the CMV (+) group, while the mean total medical cost was US$75,344 (±43,821) in the CMV (-) group. Moreover, transfusion and antimicrobial use was observed as the major medication cost component, which is suggestive of the indirect effect of CMV episodes.Conclusion: This study demonstrated that CMV episodes post allo-HSCT were associated with increased HCRU and cost.

The combination of elbasvir and grazoprevir for the treatment of chronic HCV infection in Japanese patients: a randomized phase II/III study.

BACKGROUND: Elbasvir (EBR) in combination with grazoprevir (GZR) has demonstrated efficacy in patients with hepatitis C virus (HCV) infections in trials primarily conducted in the USA and Europe. We investigated the safety and efficacy of EBR in combination with GZR in Japanese patients with chronic HCV infection, with or without cirrhosis. METHODS: The study was conducted in two parts. In part 1, noncirrhotic patients were randomized 1:1 to receive EBR (50 mg) in combination with GZR (50 or 100 mg) once daily for 12 weeks. In part 2, noncirrhotic patients were randomized 3:1 to receive immediate or deferred treatment with EBR (50 mg) and GZR (100 mg, determined in part 1) for 12 weeks; cirrhotic patients received open-label immediate treatment. The primary efficacy end point was the rate of sustained virologic response 12 weeks after completion of the study treatment. RESULTS: In part 1, 63 patients were randomized to receive EBR in combination with GZR at a dose of 50 mg (n = 31) or 100 mg (n = 32). The SVR12 rates were 100% with GZR at a dose of 50 mg and 96.8% with GZR at a dose of 100 mg. Tolerability was similar in both arms. In part 2, 301 noncirrhotic patients were randomized to receive immediate treatment (n = 227) or deferred treatment (n = 74), and 35 cirrhotic patients were enrolled. The SVR12 rates were 96.5% and 97.1% after immediate treatment in noncirrhotic and cirrhotic patients respectively. Safety was generally similar between immediate and deferred treatment. CONCLUSION: Treatment with EBR in combination with GZR for 12 weeks is effective and well tolerated in Japanese patients with chronic HCV infection. CLINICALTRIALS. GOV IDENTIFIER: NCT02203149.

Efficacy and safety of losartan 100 mg/hydrochlorothiazide 12.5 mg in Japanese subjects with essential hypertension: two randomized, controlled trials.

Two randomized studies were designed to assess the safety, tolerability and efficacy of losartan 100 mg (L100) plus hydrochlorothiazide 12.5 mg (H12.5) in a single fixed-dose combination. In one study, subjects received losartan 50 mg (L50) plus H12.5 during an 8-week filter period. They were then randomized to either L100/H12.5 or L50/H12.5 for another 8 weeks, followed by L100/H12.5 for 44 weeks. The primary end point was safety of L100/H12.5 for 52 weeks. In the second study, subjects received L100 during an 8-week filter period. Subjects were then randomized to receive either L100/H12.5 or L100 for a further 8 weeks. The primary end point was change from baseline in sitting diastolic blood pressure (SiDBP) at week 8. Safety was assessed throughout both studies. L100/H12.5 reduced SiDBP and sitting systolic blood pressure (SiSBP) at 8 weeks, and when compared with L100, the differences were statistically significant for both measures (P<0.001). L100/H12.5 reductions SiDBP for 8 weeks were comparable to L50/H12.5. The efficacy of L100/H12.5 was maintained to week 52. Drug-related adverse events with an incidence ⩾ 2% in the L100/H12.5 group during the 52-week extension period were an increase in aspartate aminotransferase and in blood uric acid. Additionally, mean uric acid levels were reduced by 0.57 mg dl(-1) from baseline with long-term treatment with L100/H12.5 in subjects whose baseline uric acid level was >7.0 mg dl(-1). In conclusion, L100/H12.5 was shown to be more effective than L100 at reducing SiDBP and SiSBP and showed good tolerability in Japanese patients with essential hypertension.

Efficacy and safety of sitagliptin monotherapy in Japanese patients with type 2 diabetes.

Efficacy and tolerability of sitagliptin, a dipeptidyl peptidase-4 inhibitor, were assessed in Japanese patients with type 2 diabetes. In a multicenter, double-blind, randomized, placebo-controlled trial in Japan, 151 patients with inadequate glycemic control [HbA(1c) > or =6.5% to <10%, fasting plasma glucose (FPG) > or =126 to < or =240 mg/dL] were randomized to once-daily sitagliptin 100mg or placebo for 12 weeks. After 12 weeks, the least squares (LS) mean change from baseline HbA(1c) was -0.65% (95% CI: -0.80, -0.50) with sitagliptin versus 0.41% (0.26, 0.56) with placebo [between-group difference=-1.05% (-1.27, -0.84); p<0.001]. LS mean change from baseline FPG was -22.5mg/dL (95% CI: -28.0, -17.0) with sitagliptin versus 9.4 mg/dL (3.9, 14.9) with placebo [between-group difference=-31.9 mg/dL (95% CI: -39.7,-24.1); p<0.001]. More patients achieved HbA(1c) <7% or <6.5% with sitagliptin than with placebo (p<0.001). Following a meal tolerance test, 2-h postprandial glucose was significantly reduced with sitagliptin relative to placebo. Clinical and laboratory adverse experiences were similar between treatments, with no reported hypoglycemia adverse events with sitagliptin. Body weight was unchanged relative to baseline in the sitagliptin group (-0.1 kg), but significantly (p<0.01) different relative to the placebo group (-0.7 kg). In this study, once-daily sitagliptin 100mg for 12 weeks improved fasting and postprandial glycemic control and was generally well tolerated in Japanese patients with type 2 diabetes.

Effects of particulate matter on daily mortality in 13 Japanese cities.

BACKGROUND: In recent years, numerous reports demonstrating the relationship between an increase in the concentration of fine particulate matter (PM2.5) and daily mortality have been released in the United States and Europe. There have been few studies that clearly characterize the short-term effects of particulate matter on the mortality in Japan. We conducted data analysis to investigate the short-term effects of suspended particulate matter (SPM) on mortality in Japan. METHODS: In this study, we used data sets from the 13 largest cities containing data on the daily mortality of residents aged 65 years or older, concentrations of air pollutants including SPM, temperature, and humidity. Risk ratios for mortality resulting from respiratory diseases, cardiovascular diseases, and all causes other than accidents, from 1990 through 1994, were summarized using a generalized additive model (GAM) and a meta-analysis of random effect model. RESULTS: The risk ratios for an increase of 10 microg/m3 in SPM concentrations adjusted for SO2, NO2, CO, Ox, temperature, and humidity were 1.0077 for all causes of mortality, 1.0109 for respiratory diseases, and 1.0091 for cardiovascular diseases, and the lower limits of the 95% confidence intervals for the risk ratios were greater than one for all cases. With regards to the effects of time lag, risk ratios were higher for the SPM concentrations on the day when the mortality was recorded, and the preceding day. CONCLUSIONS: These results suggest a positive relationship between SPM concentrations and daily mortality in Japan.