Plasma and albumin-free recombinant factor VIII: pharmacokinetics, efficacy and safety in previously treated pediatric patients
V S Blanchette, A D Shapiro, R J Liesner, F Hernández Navarro, I Warrier, P C Schroth, G Spotts, B M Ewenstein, rAHF-PFM Clinical Study Group, T Abshire, A Angiolillo, S Arkin, D Becton, V Blanchette, A Thompson, D DiMichele, J DiPaola, K Hoots, M Kurth, C Manno, I Ortiz, S Pipe, M Recht, F Shafer, A Shapiro, M Tarantino, I Warrier, W Y Wong, C Male, M Siimes, T Lambert, C Rothschild, H Chambost, C Negrier, E Fressinaud, H Brackmann, W Kreuz, H Pollmann, G Auerswald, A Gringeri, M van den Berg, C Altisent, F Hernandez, P Petrini, R Liesner, P Collins, V S Blanchette, A D Shapiro, R J Liesner, F Hernández Navarro, I Warrier, P C Schroth, G Spotts, B M Ewenstein, rAHF-PFM Clinical Study Group, T Abshire, A Angiolillo, S Arkin, D Becton, V Blanchette, A Thompson, D DiMichele, J DiPaola, K Hoots, M Kurth, C Manno, I Ortiz, S Pipe, M Recht, F Shafer, A Shapiro, M Tarantino, I Warrier, W Y Wong, C Male, M Siimes, T Lambert, C Rothschild, H Chambost, C Negrier, E Fressinaud, H Brackmann, W Kreuz, H Pollmann, G Auerswald, A Gringeri, M van den Berg, C Altisent, F Hernandez, P Petrini, R Liesner, P Collins
Abstract
Background: The pharmacokinetics of factor VIII replacement therapy in preschool previously treated patients (PTPs) with hemophilia A have not been well characterized.
Objectives: To assess the pharmacokinetics, efficacy and safety of a plasma-free recombinant FVIII concentrate, ADVATE [Antihemophilic Factor (Recombinant), Plasma/Albumin-Free Method, rAHF-PFM], in children < 6 years of age with severe hemophilia.
Patients/methods: Fifty-two boys, one girl, mean (+/- SD) age 3.1 +/- 1.5 years and >or= 50 days of prior FVIII exposure, were enrolled in a prospective study of ADVATE rAHF-PFM at 23 centers.
Results: The mean terminal phase half-life (t(1/2)) was 9.88 +/- 1.89 h, and the mean adjusted in vivo recovery (IVR) was 1.90 +/- 0.43 IU dL(-1) (IU kg(-1))(-1). Over the 1-6-year age range, t(1/2) of rAHF-PFM increased by 0.40 h year(-1). IVR increased by 0.095IU dL(-1)(IU kg(-1))(-1) (kg m(-2))(-1) in relation to body mass index (BMI). Patients primarily received prophylaxis. Median (range) annual joint bleeds were 0.0 (0.0-5.8), 0.0 (0.0-6.1) and 14.2 (0.0-34.5) for standard prophylaxis, modified prophylaxis and on-demand treatment, respectively. Bleeds were managed in 90% (319/354) of episodes with one or two rAHF-PFM infusions; response was rated excellent/good in 93.8% of episodes. Over a median 156 exposure days, no FVIII inhibitors were detected and no related severe adverse events or unusual non-serious adverse events were seen.
Conclusions: Children < 6 years of age appear to have shorter FVIII t(1/2) and lower IVR values than older subjects. However, these parameters increased with age (t(1/2)) and BMI (adjusted IVR), respectively. rAHF-PFM was clinically effective and well tolerated, with no signs of increased immunogenicity in previously treated young children with hemophilia A.
Source: PubMed