SummaryWhat is known and objective: SB5 is a biosimilar to the reference adalimumab (ADL) currently in development. The primary study objective was to demonstrate pharmacokinetic (PK) equivalence of SB5 to European Union-sourced adalimumab (EU-ADL), and United States-sourced adalimumab (US-ADL) in healthy subjects. Safety, tolerability and immunogenicity were also assessed as secondary objectives. Methods:In this phase I, single-blind trial, 189 healthy volunteers were randomized to a single 40 mg dose of SB5, EU-ADL or US-ADL and PK was evaluated for 71 days afterwards. Serum adalimumab concentrations were measured using an enzymelinked immunosorbent assay (ELISA) test. PK parameters were calculated based on actual sampling times relative to dosing and non-compartmental analysis methods, and equivalence was determined using predefined margins of 0.8-1.25.Results and discussion: Baseline characteristics and demographics were comparable between the three groups. Mean values of area under the concentration-time curve from time zero to infinity (AUC inf ), maximum serum concentration (C max ) and AUC from time zero to the last quantifiable concentration (AUC last ) were similar between groups, and 90% confidence interval for these parameters were within the predefined equivalence margins for all pairwise comparisons. No discontinuations due to treatment-emergent adverse events (TEAEs) or deaths were reported.Number and kind of TEAEs were comparable between the three groups and considered mild to moderate. The incidence of subjects with antidrug antibodies (ADA) and the overall incidence of neutralizing antibody (NAb) were comparable across the three groups.What is new and conclusion: The PK of SB5 was equivalent to that of EU-ADL and US-ADL. SB5 was well tolerated with similar safety and immunogenicity profile to EU-ADL and US-ADL. K E Y W O R D S bioequivalence, biosimilar, clinical pharmacokineticsThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Econometric estimators for a truncated regression model are reviewed. For each estimator, the motivations, the key assumptions, the asymptotic distribution and estimates for the asymptotic variance matrix are presented; also a new estimator is suggested. We select ®ve practical estimators among those, and compare them through a Monte Carlo study where the response variable is simulated but the covariates are drawn from a real data set. Some practical and computational issues are addressed as well.

In matched case-crossover studies, it is generally accepted that the covariates on which a case and associated controls are matched cannot exert a confounding effect on independent predictors included in the conditional logistic regression model. This is because any stratum effect is removed by the conditioning on the fixed number of sets of the case and controls in the stratum. Hence, the conditional logistic regression model is not able to detect any effects associated with the matching covariates by stratum. However, some matching covariates such as time often play an important role as an effect modification leading to incorrect statistical estimation and prediction. Therefore, we propose three approaches to evaluate effect modification by time. The first is a parametric approach, the second is a semiparametric penalized approach, and the third is a semiparametric Bayesian approach. Our parametric approach is a two-stage method, which uses conditional logistic regression in the first stage and then estimates polynomial regression in the second stage. Our semiparametric penalized and Bayesian approaches are one-stage approaches developed by using regression splines. Our semiparametric one stage approach allows us to not only detect the parametric relationship between the predictor and binary outcomes, but also evaluate nonparametric relationships between the predictor and time. We demonstrate the advantage of our semiparametric one-stage approaches using both a simulation study and an epidemiological example of a 1-4 bi-directional case-crossover study of childhood aseptic meningitis with drinking water turbidity. We also provide statistical inference for the semiparametric Bayesian approach using Bayes Factors. Copyright © 2016 John Wiley & Sons, Ltd.

Imatinib mesylate is effective for chronic myeloid leukaemia and gastrointestinal tumours. We aimed to evaluate the pharmacokinetics of a 200-mg imatinib tablet compared to 2×100-mg imatinib tablets in order to meet the regulatory requirements for marketing in Korea.An open-label, randomized, single-dose, 2-period, 2-treatment cross-over study was conducted in 28 healthy Korean male volunteers. Subjects were administered a 200-mg imatinib tablet and 2×100-mg imatinib tablets under a fasting state according to a randomly assigned order with a 2-week wash-out period. Serial blood samples were collected up to 72 h post-dose. The pharmacokinetic parameters were calculated using non-compartmental methods.A total of 28 subjects were enrolled and 23 subjects completed the study. There were no serious adverse events during the study. 23 mild to moderate adverse events were reported (11 events with 200-mg imatinib vs. 12 events with 2×100-mg imatinib) and subjects recovered without sequelae. The Cmax value was 922.8±318.8 μg/L at 3.15 h for 200-mg imatinib tablet, and 986.3±266.0 μg/L at 2.91 h for the 2×100-mg imatinib tablet. The AUClast of 200-mg and 2×100-mg tablets were 13 084.3±39.1 and 14 131.7±3 826.2 h · μg/L, respectively. The geometric mean ratios (90% confidence intervals) for Cmax and AUClast were 0.9121 (0.8188, 1.0161) and 0.9558 (0.8685, 1.0519), respectively.A newly developed 200-mg imatinib tablet was bioequivalent to 2×100-mg imatinib tablets in healthy Korean subjects. A single-dose of either of the 2 formulations was generally well tolerated.