Djambas Khayat C, Iosava G, Romashevskaya I, Stasyshyn O, Lopez MJ, Pompa MT, Rogosch T, Seifert W. Efficacy, Safety and Pharmacokinetic Results of a Phase III, Open-Label, Multicenter Study with a Plasma-Derived Von Willebrand Factor (VWF)/Factor VIII (FVIII) Concentrate in Pediatric Patients <12 Years of Age with Hemophilia A (SWIFTLY-HA Study).
J Blood Med 2021;
12:483-495. [PMID:
34188580 PMCID:
PMC8232873 DOI:
10.2147/jbm.s299130]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 05/29/2021] [Indexed: 12/13/2022] Open
Abstract
Background
Plasma-derived von Willebrand factor/factor VIII (pdVWF/FVIII; VONCENTO®, CSL Behring) is a high-concentration, low-volume, high-purity concentrate, with a high level of VWF high-molecular-weight multimers and a VWF/FVIII ratio of ~2.4:1.
Methods
This study (NCT01229007) investigated the pharmacokinetics (PK), efficacy and safety of pdVWF/FVIII in 35 previously treated (minimum 20 exposure days [EDs]) pediatric patients (<12 years) with severe hemophilia A. PK was evaluated with a single 50 IU FVIII/kg dose of pdVWF/FVIII. Efficacy and safety analyses were performed during on-demand treatment (n=17) or prophylaxis (n=18) for up to 100 EDs with a maximum study duration of 12 months.
Results
PK profiles were similar for patients aged <6 years and those aged 6–12 years, and, as expected, the youngest patients had an increased clearance. On-demand patients reported 320 non-surgical bleeding (NSB) events and received a median number of 29.0 infusions (median dose 34.2 IU FVIII/kg). Hemostatic efficacy was assessed by the investigator as excellent/good in all cases (24%/76%). The 18 patients in the prophylaxis arm experienced 173 NSB events (97 NSBs [56%] in three patients). Five patients (28%) had no NSB events. Overall, patients received a median number of 92 infusions (median dose 30.6 IU FVIII/kg). The majority of bleeds (92%) were successfully controlled with only one infusion. Hemostatic efficacy was assessed by the investigator as excellent (86%) or good (14%). Inhibitors occurred in three patients of which two were transient (low titer) and one persisted (high titer). These three patients had known risk factors for inhibitor development.
Conclusion
This study demonstrated comparable PK profiles for pediatric patients aged <6 years and aged 6–12 years, and an excellent efficacy and safety profile in this population. The adverse events reported were mostly mild to moderate with inhibitor rates within the expected incidence range.
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