Idarucizumab Reverses Dabigatran Anticoagulant Activity in Healthy Chinese Volunteers: A Pharmacokinetics, Pharmacodynamics, and Safety Study.

ABSTRACT

INTRODUCTION: Idarucizumab is a humanized monoclonal antibody fragment that specifically binds to dabigatran with high affinity and reverses its anticoagulant effect. This study investigated the pharmacokinetics (PK) and pharmacodynamics (PD) of idarucizumab in healthy Chinese subjects at steady state of dabigatran and explored the effect of idarucizumab on PK and PD of dabigatran. METHODS: Twelve subjects received dabigatran etexilate treatment alone (220 mg twice daily, b.i.d., oral). After a washout period, the 12 subjects again received dabigatran etexilate (220 mg b.i.d., oral) and idarucizumab (2.5 + 2.5 g, intravenous) 2 h after the last administration of dabigatran etexilate. RESULTS: The geometric mean (gMean) values of area under the plasma concentration-time curve (AUC0-∞) and maximum concentration (Cmax) were 44,200 nmol h/L and 30,900 nmol/L, respectively. An amount of 35.3 µmol of idarucizumab, corresponding to 33.8% of the total dose, was excreted by urine over 72 h. The area under the effect (AUECabove,2-12) in the presence and absence of idarucizumab was close to zero for all coagulation parameters, diluted thrombin time (dTT), ecarin clotting time (ECT), activated partial thromboplastin time (aPTT), and thrombin time (TT), which indicated the reversal of dabigatran anticoagulation by idarucizumab. There were no serious adverse events reported in this study. No subject tested positive for anti-idarucizumab antibodies. CONCLUSION: Idarucizumab was well tolerated and no subject tested positive for anti-idarucizumab antibodies in this study. PK and PD of idarucizumab in healthy Chinese subjects at a steady state of dabigatran were comparable with those in Japanese and Caucasian subjects. CLINICAL REGISTRATION ClinicalTrials.gov Identifier No. NCT03086356.