Pharmacokinetics, Pharmacodynamics, and Safety of E6011, a Novel Humanized Antifractalkine (CX3CL1) Monoclonal Antibody: A Randomized, Double-Blind, Placebo-Controlled Single-Ascending-Dose Study.

E6011 is a novel humanized antifractalkine (FKN) monoclonal antibody being developed as a therapeutic target for Crohn's disease, rheumatoid arthritis, and primary biliary cholangitis. This study was a randomized, double-blind, placebo-controlled single-ascending-dose study of intravenous administration of E6011 (0.0006-10 mg/kg) in healthy Japanese adult men (n = 64). The starting dose was the minimum anticipated biological effect level (MABEL). MABEL was estimated by extrapolating results of a pharmacokinetic/pharmacodynamic (PK/PD) model relating E6011 exposure and suppression of free soluble FKN using data obtained from cynomolgus monkeys. Safety assessments consisted of monitoring and recording adverse events, laboratory tests, vital signs, intensive electrocardiograms, and chest x-rays. Blood samples to determine PK, PD (serum total FKN concentration), and serum anti-E6011 antibody were collected. Noncompartmental analysis was used to derive PK parameters. Single intravenous infusions of E6011 were safe and well tolerated in healthy subjects. Serum E6011 concentrations showed triphasic elimination. An increase in serum total FKN concentration was observed, confirming target engagement. The dose strategy for patient studies is to select regimens that will attain a minimum serum E6011 exposure of 10 µg/mL, identified as the minimum concentration needed to saturate the target-mediated elimination pathway. Model-based drug development from preclinical stage was successful in identifying dose regimens for clinical testing.

Pharmacokinetics of Perampanel in Healthy Korean, White, and Japanese Adult Subjects.

Perampanel is a highly selective, orally active, noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist that has been approved in many countries as a treatment for partial-onset seizures and primary generalized tonic-clonic seizures. The pharmacokinetics (PK) of perampanel following multiple doses in healthy Korean, white, and Japanese male subjects were assessed in 3 studies. Noncompartmental PK parameters were derived from plasma concentration-time data. At steady state of perampanel 2-, 4-, and 6-mg oral multiple administration, perampanel was rapidly absorbed, as plasma perampanel concentration reached maximum concentration after 0.55-1 hour (median) after dosing in all 3 ethnic groups. The elimination was slow, with terminal elimination phase half-life values ranging from 63.9-129 hours (mean) for doses of 2-6 mg; there was no specific tendency suggesting a dose-related effect, and perampanel PK were linear in Korean subjects. There were no clinically relevant ethnic differences in PK following multiple doses of perampanel 2 and 4 mg between Korean, white, or Japanese subjects. Perampanel was well tolerated by all 3 ethnic groups. This outcome indicates that with respect to PK, the dosing regimens established in white and Japanese patients are applicable to Korean patients.

Warfarin-dosing algorithm based on a population pharmacokinetic/pharmacodynamic model combined with Bayesian forecasting.

AIMS: To develop a novel warfarin-dosing algorithm based on a previous population pharmacokinetic/pharmacodynamic (PK/PD) model with Bayesian forecasting to facilitate warfarin therapy. MATERIALS & METHODS: Using information on CYP2C9 and VKORC1 genotypes, S-warfarin level, dose and international normalized ratio (INR) of prothrombin time, individual PK (apparent clearance of S-warfarin [CLs]) and PD (concentration resulting in 50% of E(max) [EC(50)]) parameters were determined by Bayesian forecasting for 45 Japanese patients. Maintenance doses were described by multiple linear regression using individually estimated PK/PD parameters and INR values. The validity of the model and a comparison with other dosing methods were evaluated by bootstrap resampling and a cross-validation method. RESULTS: The plasma concentration of S-warfarin and INR were accurately predicted from individual PK/PD parameters. The following final regression model for maintenance dose was obtained; maintenance dose = 11.2 x CLs + 0.91 x EC(50) + 2.36 x INR - 9.67, giving a strong correlation between actual and predicted maintenance doses (r(2) = 0.944). Bootstrap resampling and cross-validation showed robustness and a superior predictive performance compared with other dosing methods. On the other hand, the predictability without actual measurements (S-warfarin and INR values) and Bayesian inference was comparable to other dosing methods. CONCLUSION: A novel algorithm, based on the population PK/PD model combined with Bayesian forecasting, gave precise predictions of maintenance dose, leading to individualized warfarin therapy.