INTRODUCTION

Prophylaxis with replacement factor IX (FIX) reduces bleeding frequency and improves quality of life in haemophilia B patients. With prophylaxis, the likelihood of bleeding is lowered with increasing trough levels. New products with extended half-life (EHL) can maintain high factor activity levels over prolonged periods, compared with standard FIX products.

AIM

To evaluate the safety, efficacy and pharmacokinetics of the new recombinant FIX EHL product, nonacog beta pegol (N9-GP), using pooled data, with a focus on-but not limited to-prophylaxis at 40 IU/kg.

METHODS

N9-GP has been investigated in males with congenital haemophilia B and FIX activity ≤2% in the paradigm™ clinical trial programme. This analysis includes pooled data from five completed paradigm™ trials conducted in previously treated adults, adolescents and children, focusing on results of prophylaxis with 40 IU/kg once-weekly intravenous dosing.

RESULTS

In total, 115 previously treated patients were exposed to N9-GP. Of 54 patients (47%) treated with N9-GP 40 IU/kg once-weekly prophylaxis, 72% experienced no spontaneous bleeds over 1 year. In all patients receiving 40 IU/kg once-weekly, median overall annualized bleeding rate (ABR) was 1.03 (interquartile range 0.00; 2.89); median spontaneous ABR was 0.00 (0.00; 0.80). No patients developed inhibitors. Estimated mean steady-state trough levels with N9-GP 40 IU/kg once-weekly were ≥15% overall; 27.3% in adolescents and adults.

CONCLUSION

N9-GP 40 IU/kg once-weekly was well tolerated and effective in preventing bleeding, maintaining mean FIX activity levels ≥15% across all age groups. N9-GP may provide a new treatment option for preventing bleeding in haemophilia B patients.