LAUSR

Abstract 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. 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 annualised bleeding rates 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 12 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 were 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. 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. 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 annualised bleeding rates 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 12 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 were 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. Plain Language Summary This research article gives further information about how well damoctocog alfa pegol works, and how safe it is, in those patients who were aged twelve to less-than-eighteen (“adolescents”) when they joined the PROTECT VIII clinical trial in patients 12–65 years with haemophilia A. People living with haemophilia A lack a part of their blood that normally allows clots to form. Damoctocog alfa pegol is a replacement for this missing “clotting factor”; it has also been altered to allow it to stay in the body for longer than other clotting factors, allowing for less frequent infusions. As children become adolescents and begin to manage their own factor replacement, rather than being helped by parents or others who take care of them, a treatment with less infusions is easier to follow. A clotting factor that stays in the body for longer, like damoctocog alfa pegol, might be useful for these adolescent patients. There were twelve people who were adolescents when they joined the PROTECT VIII trial. They spent an average of 4 years in the trial and had on average 1.8 bleeds every year. During the last 6 months of treatment, 8 patients had no bleeds. No study-drug-related serious adverse events were seen, no patient stopped treatment due to an adverse event, no deaths happened and no patients became immune to the treatment. This young, active patient group may benefit from the longer and more flexible dosing offered by damoctocog alfa pegol.