Inhibitor development according to concentrate after 50 exposure days in severe hemophilia: data from the European HAemophilia Safety Surveillance (EUHASS)

摘要: BackgroundPatients with hemophilia have a life-long risk of developing neutralizing antibodies (inhibitors) against clotting factor concentrates. After the first 50 exposure days (EDs), ie, in previously treated patients (PTPs), data on inhibitor development are limited.ObjectivesTo report inhibitor development according to factor (F)VIII or FIX concentrate use in PTPs with severe hemophilia A and B.MethodsInhibitor development in PTPs was collected since 2008 from 97 centers participating in European HAemophilia Safety Surveillance. Per concentrate, inhibitors were reported quarterly and the number of PTPs treated annually. Incidence rates (IRs)/1000 treatment years with 95% CIs were compared between concentrate types (plasma derived FVIII/FIX, standard half-life recombinant FVIII/FIX, and extended half-life recombinant (EHL-rFVIII/IX) concentrates using IR ratios with CI. Medians and IQRs were calculated for …