Factors contributing to the nonlinear pharmacokinetics of astegolimab: a close examination of potential causes

Aim: This paper describes a case study of an antibody therapeutic targeting a membrane-bound receptor, also present in systemic circulation, as a soluble receptor. During phase I studies of astegolimab, nonlinear pharmacokinetics (PKs) were observed. We investigated the potential contribution of antidrug antibodies, target-mediated drug disposition and assay format. Materials & methods: A more target-tolerant assay was developed, and a subset of phase I samples were evaluated in both free and total PK assay formats. Results & conclusion: Our results demonstrate that there were two main contributors to PK nonlinearity: soluble target interference in the free PK assay, in addition to target-mediated drug disposition. Antidrug antibody status did not significantly impact PK.

Monoclonal antibodies for severe asthma: Pharmacokinetic profiles

Several monoclonal antibodies (mAbs) (omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab) are currently approved for the treatment of severe asthma. They have complex pharmacokinetic profiles. These profiles are unique in that they are dependent on their structure as well as can be markedly influenced by the biology of their target antigen, but their general behaviour can still be considered a class property, similar to their endogenous IgG counterpart. They cannot be administered by oral route, have a slow distribution into tissue, are metabolized to peptides and amino acids in several tissues but are protected from degradation by binding to protective receptors (the FcRn), which explains their long elimination half-lives. Their clearance is nonlinear because of the saturation of the target-mediated elimination. Also anti-drug antibody (ADA) response and off-target binding, as well as their glycosylation pattern, can influence the pharmacokinetics of mAbs.

Development and validation of indirect and generic immunoassays to quantify free and total evolocumab in rat serum

Aim: Evolocumab is a human monoclonal antibody used in the treatment of cardiovascular diseases, which targeted proprotein convertase subtilisin kexin type 9. To accurately quantify free (including partially bound) and total evolocumab concentrations in serum, indirect and generic ELISA methods were developed and validated in rat serum. Results: Indirect ELISA was accurate and precise over the concentration range of 23.4–1500 ng/ml, and the method was validated for selectivity, specificity, accuracy and precision, dilution linearity, parallelism and stability. Similarly, generic antihuman IgG ELISA method was validated for selectivity, accuracy and precision, and dilution linearity. Moreover, incurred sample reanalysis were carried out for the above two methods, and the percent difference met the acceptable criteria. Conclusion: The validated methods can be effectively used to evaluate pharmacokinetics of free and total evolocumab after subcutaneous administration of evolocumab to rats.