Long-term efficacy and safety of damoctocog alfa pegol prophylaxis in patients with haemophilia A aged 12-<18 years at enrolment into PROTECT VIII.

Introduction The phase 2/3 PROTECT VIII study demonstrated long-term efficacy and safety of damoctocog alfa pegol (BAY 94-9027; Jivi®), a B-domain-deleted recombinant factor VIII (FVIII), site-specifically PEGylated to improve its pharmacokinetic profile. Aim We report a post hoc assessment of bleeding and safety outcomes in the subgroup of patients, aged 12-<18 years at enrolment. Method PROTECT VIII was a multicentre, open-label study of previously treated males aged 12-65 years with severe haemophilia A (FVIII<1%). Twelve patients were included in this analysis. All received damoctocog alfa pegol prophylaxis for the total time in study (median [range] time in study 4.0 [1.3-6.2] years). Results Overall median (Q1; Q3) total and joint ABRs were 1.8 (0.4; 5.1) and 0.7 (0.2; 1.8), respectively for the entire study. During the last 6 months of treatment, eight (66.7%) and ten (83.3%) out of twelve patients experienced zero total and joint bleeds, respectively. No patient developed FVIII inhibitors. No deaths or thrombotic events were reported. Conclusion Efficacy and safety of damoctocog alfa pegol was confirmed in adolescent patients with haemophilia A, with data for up to 6 years supporting its use as a long-term treatment option in this group as they transition into adulthood.