Thirty Japanese (J) and 32 American (A) healthy subjects received single doses of etanercept by subcutaneous injection, in 3 separate trials. Serum samples were collected for 480 hours after dosing. Concentrations were determined using enzyme-linked immunosorbent assay methods. Pharmacokinetic parameters were calculated using both non-compartmental and compartmental methods. Etanercept was slowly absorbed, with mean+/-SD time to maximum serum concentration of 47+/-15 hours (J), and 51+/-20 hours (A). The maximum serum concentration and area under the concentration time curve increased for doses 10 mg, 25 mg, and 50 mg, in a linear relationship. Etanercept was slowly eliminated, with observed mean+/-SD half-life of 80+/-25 hours (J) and 75+/-15 hours (A) and mean+/-SD apparent clearance of 144+/-65 mL/h (J) and 132+/-74 mL/h (A). Very low concentrations of etanercept were observed in the urine samples collected in the Japanese subjects. All adverse reactions observed resolved without issue, and none required discontinuation from the study.

Plasma β-amyloidx-40 levels increased with increasing doses of bapineuzumab. Bapineuzumab was safe and well tolerated at all doses in Japanese patients with mild to moderate Alzheimer's disease. Geriatr Gerontol Int 2016; 16: 644-650.

The validity of pharmacokinetic parameters estimated by the maximum a posteriori probability (MAP) Bayesian method was investigated by simulation studies. A 1-compartment model with bolus intravenous administration was used as a pharmacokinetic model, and the coefficients of variation for the parameters and residual error were set at 30% and 10%, respectively. The accuracy of the posterior modes of pharmacokinetic parameters estimated by the MAP Bayesian method was assessed by the difference between the true value and the estimated value. The results showed that the accuracy of the Bayesian estimation depended on sampling times and on the differences between the prior means and individual true parameter values. For assessing the reliability and accuracy of the Bayesian estimation, the authors suggest using the whole posterior distribution of the pharmacokinetic parameters to describe the 95th percentile range for predicted blood concentration profiles. The authors believe that the proposed procedures provide helpful information for evaluating the Bayesian estimation of pharmacokinetic profiles.

<b><i>Background:</i></b> Tofacitinib is an oral, small molecule Janus kinase inhibitor approved in Japan for the treatment of ulcerative colitis (UC). Differences in the safety profile of tofacitinib in Japanese patients versus the global population, such as a higher risk of herpes zoster, have been reported. <b><i>Objectives:</i></b> We conducted post hoc analyses of tofacitinib treatment in Japanese patients with moderate-to-severe UC in two global phase III studies. <b><i>Methods:</i></b> In OCTAVE Induction 1 (NCT01465763), 62 patients were randomized to placebo or tofacitinib 10 mg twice daily (b.i.d.). In OCTAVE Sustain (NCT01458574), 39 patients with clinical response in OCTAVE Induction 1 were re-randomized to placebo, tofacitinib 5 mg, or 10 mg b.i.d. Efficacy endpoints included: remission (primary endpoint; total Mayo score ≤2; no individual subscore &#x3e;1; rectal bleeding subscore 0); mucosal healing (Mayo endoscopic subscore ≤1); clinical response (≥30% and ≥3-point decrease from induction study baseline total Mayo score; decrease in rectal bleeding subscore ≥1 or absolute subscore ≤1). Adverse events (AEs) and clinical laboratory parameters were recorded. <b><i>Results:</i></b> At week 8 of OCTAVE Induction 1, 22.4% of patients achieved remission with tofacitinib (placebo, 7.7%). At week 52 of OCTAVE Sustain, 31.3% and 66.7% of patients receiving tofacitinib 5 and 10 mg b.i.d., respectively, achieved remission (placebo, 9.1%). The occurrence of AEs or serious AEs in Japanese patients was generally similar to that in the global study population, with no new or unexpected safety risks observed. <b><i>Conclusions:</i></b> Although patient numbers were small, tofacitinib demonstrated numerically greater efficacy versus placebo among Japanese patients in OCTAVE Induction 1 and OCTAVE Sustain, with a safety profile consistent with that of the global study population.

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