Introduction: Omfiloctocog alfa, the first China-developed recombinant factor VIII (FVIII), demonstrated efficacy and safety of prophylaxis in previously treated patients (PTPs) aged ≥12 years with severe hemophilia A in China.
Aims: To investigate efficacy, safety and pharmacokinetics (PK) of omfiloctocog alfa in pediatric PTPs with severe hemophilia A in China.
Methods: PTPs (>50 exposure days [ED] for Chinese patients aged <6 years; >150 EDs for patients aged 6-12 years) were treated with omfiloctocog alfa at 25-50 IU/kg every other day or three times per week for 24 weeks. PK was evaluated after single injection of 50 IU/kg. The primary efficacy endpoint was annualized bleeding rate (ABR).
Results: A total of 69 patients were enrolled (<6 years, n = 35; 6-12 years, n = 34) and mean exposure to omfiloctocog alfa was 78.9 days. Mean half-life was 6.7 and 10.2 h in children < 6 years and 6-12 years, respectively. Estimated mean ABRs of all patients were 4.05 for overall bleeding episodes and 1.38 for spontaneous bleeding episodes. Of 127 bleeding episodes, the success rate was 92.1%. 39.7% patients did not experience any bleeding episodes and the mean weekly dose of FVIII was 109.1 IU/kg for these patients. 83% bleeding episodes were controlled with ≤2 injections. Adverse reactions occurred in 2.9% of the patients. One 2-year-old patient developed inhibitors after 12 EDs and it resolved with omfiloctocog alfa immune tolerance induction.
Conclusion: Omfiloctocog alfa was efficacious and well tolerated for the prevention and treatment of bleeding in Chinese pediatric PTPs with severe hemophilia A.
Keywords: children; hemophilia A; omfiloctocog alfa; pharmacokinetics; prophylaxis.
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