Plasma-derived von Willebrand factor/factor VIII (pdVWF/FVIII) has a favorable risk-benefit profile based on phase 3 results that evaluated the pharmacokinetics and safety of the treatment published in the Journal of Blood Medicine.
In previous studies, factor replacement therapy as prophylaxis has been shown to reduce joint damage and total bleeds. Some patients develop FVIII inhibitors with recombinant FVIII products. Previous studies in adults have demonstrated the efficacy and safety of plasma-derived FVIII products.
The phase 3 study evaluated the pharmacokinetics (PK), safety and efficacy of pdVWF/FVIII in children younger than 12 years with severe hemophilia A who had previously been treated with a FVIII product for at least 20 exposure days.
The study included 35 patients, with 18 receiving prophylactic treatment and 17 receiving on-demand treatment. Study participation was a median of 300 days.
In the on-demand arm, patients reported 320 non-surgical bleeding (NSB) events, and patients received a median of 29 infusions. In all cases, the hemostatic efficacy as assessed by the investigator was considered excellent (24.2%) or good (75.8%).
In the prophylactic arm, patients had a median of 92 infusions and experienced 173 NSB events. A total of 56% of these events were reported by 3 patients. The investigator assessed the hemostatic efficacy as excellent (86%) or good (14%).
A total of 12 patients (66.7%) in the prophylaxis arm reported 64 treatment-emergent adverse events (TEAEs), while 11 (64.7%) in the on-demand arm had 33 TEAEs. Cough was the most common TEAE, followed by pyrexia, rhinitis, FVIII inhibition, and rash.
Overall, the results of this study were similar to the PK, safety, and efficacy results of pdVWF/FVIII in adults and adolescents. Therapy with pdVWF/FVIII was well-tolerated and effective as on-demand and prophylactic therapy in children younger than 12 years.
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Djambas Khayat C, Iosava G, Romashevskaya I, et al. 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. doi:10.2147/JBM.S299130