Pharmacokinetics (PK) of S/D treated anti-D immunoglobulin after intramuscular injection in healthy volunteers: gender differences in PK.

The aim of this study was to investigate the pharmacokinetic profile of the new solvent/detergent (S/D) formulation of an anti-D IgG preparation, and to evaluate gender differences. RhD-negative subjects (m/f=10/8) received a single i.m. injection of 250 microg anti-D (Partobulin SDF). There was a rapid increase in median anti-D titers over the first 2 days, followed by a plateau from days 2-7. Interestingly, women had a higher maximum concentration (Cmax) of anti-D and a lower volume of distribution at steady state (Vss) than men. The half-life calculated in this study was 23 days. Thus, results are comparable to published data of the non-S/D treated predecessor product. Because of the observed gender differences in the pharmacokinetics we recommend to pursue the evaluation of sex differences in the pharmacokinetics of other antibodies during early phase drug development.