Long‐term safety and efficacy of N8‐GP in previously treated pediatric patients with hemophilia A: Final results from pathfinder5

BACKGROUND: N8‐GP (turoctocog alfa pegol; Esperoct(®), Novo Nordisk A/S, Bagsvaerd, Denmark) is a glycoPEGylated, extended half‐life human recombinant factor VIII (FVIII). OBJECTIVE: Here, we report end‐of‐trial safety and efficacy results from the completed N8‐GP pathfinder5 trial. METHODS: pathfinder5 (NCT01731600) was a multi‐national, open‐label, single‐arm, non‐randomized, non‐controlled trial in previously treated male patients aged <12 years old with severe hemophilia A that comprised a main and an extension phase. During the main phase, patients received twice‐weekly N8‐GP 60 IU/kg for 50 exposure days (~26 weeks). During the extension phase, patients received the same regimen until the end of trial (first patient in main phase, 20 February 2013; trial end, 28 September 2018). RESULTS: Sixty‐eight patients were exposed to N8‐GP for a median time of ~4.9 years on regimen. Of the 63 patients who started in the extension phase, 62 completed the trial. No FVIII inhibitors (≥0.6 BU) or other safety concerns were detected. The overall estimated annualized bleeding rate was 1.08 (median 0.81), and nearly 20% of patients had no bleeds during the entire trial. The proportion of patients with no annual bleeds increased with time, with 56% of patients experiencing no bleeds and 86% experiencing no spontaneous bleeds during the fourth year of exposure. All baseline target joints of patients who participated in both phases of this trial were resolved in slightly over 2 years. CONCLUSION: Overall, data from the completed pathfinder5 trial show that long‐term (median 4.9 years) N8‐GP treatment was efficacious and well tolerated in previously treated pediatric patients with severe hemophilia A.