TY - JOUR
T1 - Measurement of extended half-life recombinant FVIII molecules: In vitro and ex vivo evidence of relevant assay discrepancies
AU - Lancellotti, Stefano
AU - Sacco, Monica
AU - Tardugno, Maira
AU - Mancuso, Maria Elisa
AU - De Cristofaro, Raimondo
PY - 2023
Y1 - 2023
N2 - Background: Extended half-life recombinant FVIII products (EHL-rFVIIIs) have been engineered to improve the pharmacokinetic profile of FVIII, enabling better hemostatic protection with a reduced number of injections in persons with hemophilia. Previous studies showed several discrepancies in FVIII activity (FVIII:C) measurements for EHL-rFVIIIs comparing one-stage clotting assay (OSA) and chromogenic assay (CSA), although a systematic investigation of this phenomenon is still lacking. Objective: Evaluation of the accuracy and precision of measurement of all available EHL-rFVIIIs with 5 different assays both in vitro and ex vivo. Methods: Damoctocog alfa pegol, rurioctocog alfa pegol, turoctocog alfa pegol, and efmoroctocog alfa were tested with 3 OSA types: (1) aPTT-based commercial reagents with colloidal silica (Synthasil, Werfen-IL); (2) ellagic acid, Synthafax (Werfen-IL); and (3) OSA calibrated with each EHL-rFVIII product and colloidal silica. Measurements were also carried out with 2 different commercially available CSA reagents (Coamatic Factor VIII, Chromogenix-Werfen) and Trinichrom FVIII (Tcoag-Stago). A Bland-Altman analysis was performed to compare all assays. Results: The simple OSA showed significant discrepancies between the expected and measured EHL-rFVIII concentrations as CSA methods, whereas the calibrated OSA assay was accurate and precise in determining the activity of all EHL-rFVIIIs in the in vitro setting. Comparable results were found using ex vivo plasma samples. Conclusion: In this study, only OSA with a calibration curve constructed with each EHL-rFVIII product showed acceptable accuracy and precision in EHL-rFVIIIs measurements.
AB - Background: Extended half-life recombinant FVIII products (EHL-rFVIIIs) have been engineered to improve the pharmacokinetic profile of FVIII, enabling better hemostatic protection with a reduced number of injections in persons with hemophilia. Previous studies showed several discrepancies in FVIII activity (FVIII:C) measurements for EHL-rFVIIIs comparing one-stage clotting assay (OSA) and chromogenic assay (CSA), although a systematic investigation of this phenomenon is still lacking. Objective: Evaluation of the accuracy and precision of measurement of all available EHL-rFVIIIs with 5 different assays both in vitro and ex vivo. Methods: Damoctocog alfa pegol, rurioctocog alfa pegol, turoctocog alfa pegol, and efmoroctocog alfa were tested with 3 OSA types: (1) aPTT-based commercial reagents with colloidal silica (Synthasil, Werfen-IL); (2) ellagic acid, Synthafax (Werfen-IL); and (3) OSA calibrated with each EHL-rFVIII product and colloidal silica. Measurements were also carried out with 2 different commercially available CSA reagents (Coamatic Factor VIII, Chromogenix-Werfen) and Trinichrom FVIII (Tcoag-Stago). A Bland-Altman analysis was performed to compare all assays. Results: The simple OSA showed significant discrepancies between the expected and measured EHL-rFVIII concentrations as CSA methods, whereas the calibrated OSA assay was accurate and precise in determining the activity of all EHL-rFVIIIs in the in vitro setting. Comparable results were found using ex vivo plasma samples. Conclusion: In this study, only OSA with a calibration curve constructed with each EHL-rFVIII product showed acceptable accuracy and precision in EHL-rFVIIIs measurements.
KW - blood coagulation
KW - coagulation factor VIII
KW - congenital
KW - extended half-life rFVIII
KW - factor VIII deficiency
KW - tests
KW - therapeutic drug monitoring
KW - blood coagulation
KW - coagulation factor VIII
KW - congenital
KW - extended half-life rFVIII
KW - factor VIII deficiency
KW - tests
KW - therapeutic drug monitoring
UR - http://hdl.handle.net/10807/231849
U2 - 10.1016/j.rpth.2023.100070
DO - 10.1016/j.rpth.2023.100070
M3 - Article
SN - 2475-0379
VL - 7
SP - 100070
EP - 100080
JO - Research and Practice in Thrombosis and Haemostasis
JF - Research and Practice in Thrombosis and Haemostasis
ER -