Efficacy assessment of a new clotting factor concentrate in haemophilia A patients, including prophylactic treatment

Abstract

Currently, efficacy of a new factor concentrate is mostly judged by its ability to achieve haemostasis after a bleeding episode. However, in patients on prophylaxis, the effectiveness in preventing bleeds, and thus joint damage, is most important. An albumin-free recombinant factor VIII (FVIII) concentrate was introduced in the Netherlands in 2004. In this study, the efficacy of a new recombinant plasma/albumin-free FVIII concentrate (rAHF-PFM, Advate) was assessed by comparing bleeding frequency and factor consumption before and after switching to the new product, on both prophylactic and on-demand treatment. Eighty-two previously treated haemophilia A patients with at least 1-year clinical follow-up were included in this study. Data on 410 patient-years were analysed, including 165 patient-years on other clotting factor products, and 245 patient-years on the new concentrate. In total, 19 628 368 IU of other factor concentrates were administered, to treat 839 bleeds, including 578 joint bleeds and cover 104 years of prophylactic treatment. For rAHF-PFM 33 082 250 IU FVIII, were used to treat 1144 bleeds, including 734 joint bleeds and cover 175 years of prophylactic treatment. No inhibitors, seroconversions or other serious adverse events were observed. Annual FVIII consumption per kg and annual number of joint bleeds before and after switching to the new albumin-free recombinant factor concentrate were similar in all patients. In conclusion, rAHF-PFM is equally effective as other clotting factor concentrates for prophylactic treatment in severe haemophilia.