No abstract

Cefiderocol, a new injectable siderophore cephalosporin antibiotic, has promising in vitro and in vivo activity against Gram‐negative bacteria including multidrug‐resistant Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae. Cefiderocol is mainly renally eliminated. The pharmacokinetics and safety of cefiderocol in subjects with renal impairment were assessed following a single 1000‐mg intravenous 1‐hour infusion of cefiderocol. Subjects with mild, moderate, or severe renal impairment and end‐stage renal disease (ESRD) requiring hemodialysis were compared with demographically (age, body mass index, and sex) matched healthy subjects with normal renal function. The effect of hemodialysis on the clearance of cefiderocol was also assessed. Total drug clearance from plasma (CL) and terminal half‐life (t1/2) correlated with renal function. Ratios (90% confidence intervals) of area under the plasma concentration‐time curve from 0 to infinity (AUC) in mild, moderate, severe, and ESRD groups compared to those with normal renal function were 1.0 (0.8‐1.3), 1.5 (1.2‐1.9), 2.5 (2.0‐3.3), and 4.1 (3.3‐5.2), respectively. Maximum plasma concentration (Cmax) was similar between renal‐impairment groups and the normal‐renal‐function group. Approximately 60% of cefiderocol was removed by hemodialysis for 3 to 4 hours. The plasma‐protein‐unbound fraction was similar between various renal function groups. The incidence of adverse events did not appear to have any correlation with the degree of renal impairment. Single 1000‐mg intravenous doses of cefiderocol were generally well tolerated in subjects with impaired renal function except for 1 subject who discontinued due to urticaria. In conclusion, renal impairment impacted AUC, CL, and t1/2 without affecting Cmax. Cefiderocol was significantly removed by intermittent hemodialysis.

Cefiderocol is a novel parenteral siderophore cephalosporin that shows potent efficacy against various Gram-negative bacteria, including carbapenem-resistant strains, in vitro and in preclinical models of infection. The aim of the present study was to evaluate the pharmacokinetics (PK), safety, and tolerability of cefiderocol after both single and multiple dosing by intravenous infusion over 60 min in healthy adult subjects. A single-ascending-dose study at doses of 100, 250, 500, 1,000, and 2,000 mg was conducted in 40 healthy Japanese males and females (6 individuals receiving the active drug and 2 individuals receiving a placebo per cohort). A multiple-ascending-dose study at doses of 1,000 (two groups) and 2,000 mg every 8 h (q8h) was conducted in 30 healthy Japanese and Caucasian males (8 individuals receiving the active drug and 2 individuals receiving a placebo per cohort). There were no serious or clinically significant adverse events (AEs) observed in either study. A single subject receiving 1,000 mg cefiderocol q8h was withdrawn due to AEs. Dose-proportional increases in the maximum plasma concentration (Cmax), the area under the concentration-time curve (AUC) from time zero to the time of the last quantifiable concentration after dosing, and the area under the concentration-time curve extrapolated from time zero to infinity were observed across the dose range of 100 to 2,000 mg. The mean plasma half-life of cefiderocol was 1.98 to 2.74 h. Cefiderocol was primarily excreted unchanged in the urine (61.5% to 68.4% of the dose). There was little accumulation of Cmax and AUC by dosing q8h, and the PK of cefiderocol did not change with multiple dosing. This study indicates that single and multiple intravenous doses of cefiderocol at up to 2,000 mg are well tolerated in healthy subjects and exhibit linear PK at doses up to 2,000 mg.

Cefiderocol, a novel parenteral siderophore cephalosporin, exhibits potent efficacy against most Gram-negative bacteria, including carbapenem-resistant strains. Since cefiderocol is excreted primarily via the kidneys, this study was conducted to develop a population pharmacokinetics (PK) model to determine dose adjustment based on renal function. Population PK models were developed based on data for cefiderocol concentrations in plasma, urine, and dialysate with a nonlinear mixed-effects model approach. Monte-Carlo simulations were conducted to calculate the probability of target attainment (PTA) of fraction of time during the dosing interval where the free drug concentration in plasma exceeds the MIC (T fϾMIC ) for an MIC range of 0.25 to 16 g/ml. For the simulations, dose regimens were selected to compare cefiderocol exposure among groups with different levels of renal function. The developed models well described the PK of cefiderocol for each renal function group. A dose of 2 g every 8 h with 3-h infusions provided Ͼ90% PTA for 75% T fϾMIC for an MIC of Յ4 g/ml for patients with normal renal function, while a more frequent dose (every 6 h) could be used for patients with augmented renal function. A reduced dose and/or extended dosing interval was selected for patients with impaired renal function. A supplemental dose immediately after intermittent hemodialysis was proposed for patients requiring intermittent hemodialysis. The PK of cefiderocol could be adequately modeled, and the modeling-and-simulation approach suggested dose regimens based on renal function, ensuring drug exposure with adequate bactericidal effect.

BackgroundThrombocytopenia represents an obstacle for invasive procedures in chronic liver disease (CLD) patients. We aimed to estimate the appropriate dose and evaluate the efficacy and safety of lusutrombopag for the treatment of thrombocytopenia before percutaneous liver radiofrequency ablation (RFA) for primary hepatic cancer in patients with CLD.MethodsIn this multicenter, randomized, double-blind, placebo-controlled study conducted in Japan, 61 CLD patients with platelet count < 50 × 103/µL at screening were randomized to placebo or lusutrombopag 2, 3, or 4 mg once daily for 7 days, followed by a 28-day post-treatment assessment period. The primary efficacy endpoint was the proportion of patients who did not require platelet transfusion before RFA. The pre-specified key secondary efficacy endpoint was the proportion of responders. Adverse events (AEs) and thrombosis-related AEs were evaluated.ResultsThe proportion of patients who did not require platelet transfusion before RFA and that of responders were significantly higher (p < 0.01) in the 2-mg (80.0, 66.7%), 3-mg (81.3, 68.8%), and 4-mg groups (93.3, 80.0%) compared with the placebo group (20.0, 6.7%) and showed a dose-dependent effect. The incidence of AEs was 97.8 and 100% in the lusutrombopag (all groups) and placebo groups, respectively; no dose-related increase was observed. Four patients experienced thrombosis-related events (one each in the placebo and 2-mg groups, and two in the 4-mg group). A total of 16 (18%) adverse drug reactions occurred in the safety analysis set.ConclusionsLusutrombopag 3 mg once daily for 7 days was effective without raising concerns about excessive increases in platelet count.Clinical trial registrationThe study is registered at JapicCTI-121944.Electronic supplementary materialThe online version of this article (10.1007/s00535-018-1499-2) contains supplementary material, which is available to authorized users.