Analysis of efficacy and safety of nonacog beta pegol in Japanese pediatric patients with hemophilia B

Abstract

Nonacog beta pegol (N9-GP, Refixia^®) is an extended half-life recombinant factor IX (FIX) product. Results of a global phase III clinical trial, paradigm 5, revealed the efficacy and safety of weekly prophylaxis with N9-GP in pediatric hemophilia B patients (FIX activity </=0.02 IU/mL), achieving a mean FIX trough level higher than 0.15 IU/mL. This study is a detailed analysis of three Japanese pediatric patients with severe hemophilia B who enrolled in the paradigm 5 study. The mean treatment duration was 3.29 years, during which seven bleeding events requiring treatment occurred in the three patients. All bleeding events were mild/moderate and responded well to a single administration of N9-GP. None of the patients developed target joints during the study period. The overall annualized bleeding rates and the annualized spontaneous bleeding rates were similar to the paradigm 5 results. There was no severe or serious adverse event, adverse event suspected to be related to the study treatment, or development of FIX inhibitors. The mean FIX trough level of the prophylactic treatment was 0.172 IU/mL, which was similar to that found in the paradigm 5 study. Only three patients were analyzed in this study; however, the results were not markedly different from those of the paradigm 5 study.