Long-term safety and efficacy of turoctocog alfa in prophylaxis and treatment of bleeding episodes in severe haemophilia A: Final results from the guardian 2 extension trial

Abstract

Introduction: Turoctocog alfa is a recombinant factor VIII (FVIII) molecule, approved for treatment and prophylaxis of bleeding in patients with haemophilia A. In the guardian 1 (adolescents/adults) and guardian 3 (children) phase 3 trials, turoctocog alfa demonstrated a favourable efficacy and safety profile. Guardian 1 or 3 completers could enrol in the guardian 2 extension. Final guardian 2 results are reported here.

Aim: Investigate long-term safety and efficacy of turoctocog alfa administered for prophylaxis and treatment of bleeds.

Methods: In this phase 3b open-label trial, previously treated males of all ages with severe haemophilia A received prophylaxis regimens of turoctocog alfa or on-demand treatment of bleeds. The primary safety endpoint was frequency of FVIII inhibitor development. Efficacy endpoints included annualized bleeding rate (ABR) during prophylaxis, haemostatic response in treatment of bleeds and number of injections required to treat bleeds.

Results: Overall, 213 patients were dosed with turoctocog alfa; 207 patients received prophylaxis; 19 received on-demand treatment. No FVIII inhibitors (≥0.6 BU) were reported. For all patients on prophylaxis, overall median ABR was 1.37 bleeds/y; success rate for treatment of bleeds was 90.2%; and 88.2% of bleeds were controlled with 1-2 injections of turoctocog alfa. For the on-demand regimen, overall median ABR was 30.44 bleeds/y; success rate for treatment of bleeds was 96.7%; and 94.9% of bleeds were controlled with 1-2 injections of turoctocog alfa.

Conclusion: Extended use of turoctocog alfa is safe and effective for prevention and treatment of bleeding episodes in previously treated patients with haemophilia A across all ages.

Keywords: annualized bleeding rate; haemophilia A; prophylaxis; recombinant factor VIII; turoctocog alfa.