Akira Okada

Objectives To examine the incidence of stroke or systemic embolic events (SSEs) and bleeding events in untreated patients with non-valvular atrial fibrillation (NVAF) after widespread use of direct oral anticoagulant agents (DOACs). Design Multicentre, non-interventional, observational, retrospective cohort study using real-world data in Japan (2016-2018). Setting The Mie, Musashino University study of NVAF, which used the Mie-Life Innovation Promotion Center Database. This is a regional clinical database involving one university hospital and eight general hospitals in Mie Prefecture in Japan. Participants Japanese patients with NVAF (n=7001). Primary and secondary outcome The incidence of SSEs and bleeding events. Results A total of 7001 patients with NAVF were registered, and 53.0% were treated with DOACs, 10.6% were treated with warfarin and 36.4% had no treatment. Additionally, 29.5% of patients with a CHADS2 (congestive heart failure, hypertension, age≥75 years, diabetes, previous stroke or transient ischemic attack) score of 3–6 were untreated. In the no treatment group, the SSE rates by the CHADS2 score (0, 1, 2 and 3–6) were 1.4%, 1.4%, 3.2% and 8.0%, respectively. The rates of bleeding events by the CHADS2 score (0, 1, 2 and 3–6) in the no treatment group were 0.7%, 1.0%, 1.2% and 2.9%, respectively. A multivariate analysis of SSEs in components of the CHADS2 showed that the adjusted HRs were 2.32 for heart failure, 1.66 for an age ≥75 years, 1.81 for diabetes mellitus and 5.84 for prior stroke or transient ischaemic attack. Conclusions Approximately one-third of the patients do not receive any anticoagulation in the modern DOAC era in Japan. The SSE rate increases by the CHADS2 score. The SSE rate is low in patients with a CHADS2 score <1, supporting no indication of anticoagulation in current guidelines. In patients with a CHADS2 score >1, the use of anticoagulant drug therapy is recommended because of a higher risk of stroke.

PURPOSE: Creatinine clearance (CCr) and pharmacokinetic parameters are markedly affected by pathophysiological changes in patients with sepsis. However, only a few reports have assessed renal function in patients with sepsis using the measured CCr. Furthermore, the administration regimen has not been sufficiently evaluated using a population PK (PPK) model across renal function broad ranges. Therefore, this study was performed to construct a meropenem PPK model for patients with sepsis using the measured CCr and evaluate the optimized meropenem dosing regimen based on the CCr. METHODS: Patients with sepsis who received intravenous meropenem at the Showa University Hospital were enrolled in this prospective observational study. The PPK model was constructed using blood samples and clinical information of patients. The probability of target attainment (PTA) indicates the likelihood of achieving 50% time above the minimum inhibitory concentration (% T > MIC) based on 10,000 virtual patients using Monte Carlo simulations. The PTA for each meropenem regimen was 50% T > MIC based on different renal functions using the Monte Carlo simulation. RESULTS: One hundred samples were collected from 31 patients. The final PPK model incorporating the measured CCr as a covariate in CL displayed the best fit. The recommended dosing regimen to achieve a PTA of 50% T > MIC of 4 mcg/mL was 1 g every 8 hours as a 3-hour prolonged infusion for patients with CCr 85-130 mL/min and 1 g every 8 hours as an 8-hour continuous infusion for patients with CCr ≥ 130 mL/min. CONCLUSIONS: This model precisely predicted meropenem concentrations in patients with sepsis by accurately evaluating renal function using the measured CCr. Extended dosing was demonstrated to be necessary to achieve a PTA of 50% T > MIC for patients with CCr ≥ 85 mL/min. Meropenem effectiveness can be maximized in patients with sepsis by selecting the appropriate dosing regimen based on renal function and the MIC.

PURPOSE: Adverse events after the use of the CDK4/6 inhibitor abemaciclib are dose-dependent. However, its pharmacokinetics varies among individuals. Abemaciclib is reportedly transported by P-glycoprotein and breast cancer resistance protein. Therefore, we evaluated whether ABCB1 and ABCG2 polymorphisms are pharmacokinetic predictive factors of abemaciclib. METHODS: A total of 45 patients with breast cancer taking abemaciclib (150 mg twice per day) for 2 weeks were evaluated to determine the associations among abemaciclib concentration; adverse events; and ABCB1 1236 T > C, 2677G > T/A, 3435C > T, and ABCG2 421C > A gene polymorphisms. RESULTS: The trough concentration of abemaciclib was significantly higher in the group with grade 2 or greater neutropenia and thrombocytopenia than in those with grades 0 or 1. For ABCB1 2677G > T/A polymorphisms, the concentration of abemaciclib tended to be higher in the homozygous group (TT + AT) than in the wild-type + heterozygous group (GG + GA + GT) (median [range], 222.8 [80.5-295.8] ng/mL vs. 113.5 [23.6-355.2] ng/mL, P = 0.09), Moreover, the ABCB1 2677G > T/A homozygous group had a higher tendency of abemaciclib withdrawal or dose reduction within 4 weeks than the wild-type + heterozygous group (odds ratio, 4.22; 95% confidence interval, 0.86-20.7; P = 0.08). No significant association was observed among abemaciclib concentration; adverse reactions; and ABCB1 1236 T > C, 3435C > T, and ABCG2 421C > A polymorphisms. CONCLUSION: ABCB1 2677G > T/A polymorphism might be a predictor of the pharmacokinetics and tolerability of abemaciclib.