Lack of ethnic differences in the pharmacokinetics and pharmacodynamics of evolocumab between Caucasian and Asian populations

AIMS: To evaluate the potential ethnic differences in the pharmacokinetics (PK) and pharmacodynamics (PD) of evolocumab in Caucasian and Asian populations using population PK/PD modelling analysis. METHODS: Data from different ethnic groups in 5 Phase I clinical trials, including two American studies, one Japanese study and two Chinese studies, were chosen for model building and evaluation. A target-mediated drug disposition model together with an indirect response model best captured evolocumab binding and the removal of unbound proprotein convertase subtilisin/kexin type 9 (PCSK9) as well as a reduction in circulating low-density lipoprotein cholesterol (LDL-C). Ethnicity and other related factors (body weight, target expression level etc.) were analysed as potential covariates. RESULTS: The estimated linear clearance and volume of evolocumab were 0.24 l day-1 and 2.75 l, respectively, which was consistent with the previous modelling results from the American trials. The time course of the LDL-C reduction was described by an indirect response model with the elimination rate of LDL-C being modulated by unbound PCSK9. The concentration of unbound PCSK9 associated with the half-maximal inhibition of LDL-C elimination was 1.28 nmol l-1 . Both the PK and PD characteristics were consistent between the Caucasian and Asian populations. CONCLUSION: The target-mediated drug disposition model successfully described the PK and PD characteristics of evolocumab, and this analysis found no significant differences in the PK/PD relationship for its LDL-C lowering effects between Caucasians and Asians.