Pharmacokinetic (PK) Assay Development for Modified Proteins

The choice depends on the target biology and study objectives. If soluble target is present at significant concentrations, free drug is often the pharmacologically active species and should be measured using an anti-idiotype reagent that binds the antigen-binding site. If total drug exposure is needed, a generic anti-Fc or modification-specific reagent can be used. We discuss this with you during the consultation to define the optimal strategy.

Depending on the modification, we can generate or source anti-idiotype antibodies, anti-PEG antibodies, anti-polysialic acid antibodies, or other modification-specific capture reagents. Each reagent is characterized for affinity and specificity to minimize cross-reactivity with endogenous components.

Yes. Our validation protocols follow ICH M10 and FDA guidance for bioanalytical method validation, covering accuracy, precision, selectivity, dilution linearity, parallelism, and stability assessments. The final validation report is suitable for inclusion in IND submissions.

We offer noncompartmental analysis (NCA) to derive Cmax, AUC, t½, and clearance. For more complex modeling, we can provide data formatted for population PK software or coordinate with your pharmacometricians. The scope is defined per project.

We commonly develop methods in human and animal plasma and serum. Other biological fluids (e.g., cerebrospinal fluid, tissue homogenates) can be considered upon consultation, subject to matrix effect evaluations.

Timelines are project-dependent and scoped during the initial consultation. We will provide a detailed schedule based on assay complexity and the number of validation runs required.