Like naturally occurring Factor VIII, AFSTYLA binds to von Willebrand factor (VWF), which helps protect it from degradation in circulation.
In the AFSTYLA phase 1 PK study:
Clearance is mathematically related to other pharmacokinetic measures, such as half-life and area under the curve—important parameters that are considered when determining optimal dosing regimens.
Samples from 27 adult patients were analyzed for predose VWF and clearance of Factor VIII after a single 50 IU/kg infusion of AFSTYLA and active comparator (with washout period). Regression lines estimated from a post hoc analysis are shown. 95% CI=95% confidence interval.2,3
References: 1. Zollner S, Raquet E, Claar P, et al. Non-clinical pharmacokinetics and pharmacodynamics of
rVlll-SingleChain, a novel recombinant single-chain factor VIII. Thromb Res. 2014;134(1):125-131. 2. Data on
file. Available from CSL Behring as DOF AFS-002. 3. Klamroth R, Simpson M, von Depka-Prondzinski M, et al.
Comparative pharmacokinetics of rVlll-SingleChain and octocog alfa (Advate®) in patients with severe
haemophilia A. Haemophilia. 2016;22:730-738.