BAY 81-8973, a full-length recombinant factor VIII: results from an International comparative laboratory field study

Introduction BAY 81‐8973 is a full‐length, unmodified, recombinant human factor VIII (FVIII) with the same primary amino acid sequence as sucrose‐formulated recombinant FVIII but produced with certain more advanced manufacturing technologies. Aim This global laboratory study evaluated variability in measurement of BAY 81‐8973 using one‐stage and chromogenic assays compared with antihaemophilic factor (recombinant) plasma/albumin‐free method (rAHF‐PFM; Advate®) under assay conditions routinely used in clinical laboratories. Methods BAY 81‐8973 or rAHF‐PFM was spiked into FVIII‐deficient plasma at 0.043 (low), 0.375 (medium) and 0.865 (normal) IU mL−1. Participating laboratories analysed blinded samples and normal plasma in triplicate using their routine assay, reagents and standards. Results were analysed for intra‐ and interlaboratory variability. Results Forty‐one laboratories in 11 countries participated in the study. One‐stage assay and chromogenic assays were used by 40 and 10 laboratories, respectively; 9 laboratories used both assays. Intralaboratory variability was