PROTECT VIII kids extension study: Long-term safety and efficacy of BAY 94-9027 (damoctocog alfa pegol) in children with severe haemophilia A

Haemophilia. 2021 May;27(3):434-444. doi: 10.1111/hae.14294. Epub 2021 Mar 16.


Introduction: BAY 94-9027 (damoctocog alfa pegol; an extended half-life PEGylated recombinant factor VIII [FVIII]) demonstrated efficacy and safety in previously treated paediatric patients (PTPs) aged <12 years with severe haemophilia A in the PROTECT VIII Kids study (NCT01775618).

Aim: To evaluate the long-term safety of BAY 94-9027 in PTPs aged <12 years at enrolment.

Methods: In the PROTECT VIII Kids study, boys <12 years with severe haemophilia A were enrolled in two age cohorts (6-<12 years and <6 years) and treated prophylactically twice weekly, every 5 days or every 7 days, with BAY 94-9027 for ≥50 exposure days (EDs). Patients who had completed ≥50 EDs and ≥6 months in the main study or 12-week safety expansion study were eligible to participate in the extension. Primary safety variable was frequency of inhibitor development; main efficacy variable was annualised bleeding rate (ABR).

Results: Of 73 PTPs from the main/expansion studies, 59 (81%) entered the extension phase for a median (range) duration of 5.0 (0.4-5.9) years. Overall, 39 patients completed ≥5 years of treatment. No patients developed FVIII inhibitors/anti-PEG antibodies, and two patients aged <6 years discontinued. Median ABR for total bleeds was 1.5 (<6 years) and 1.9 (6-<12 years). Total ABR improved in the extension vs. the main study. In the last 12 months of treatment, median spontaneous ABR was 0.0 in both age groups.

Conclusions: BAY 94-9027 showed long-term safety and efficacy for the prevention and treatment of bleeds in younger and older paediatric patients with severe haemophilia A.

Keywords: FVIII; adolescents; children; damoctocog alfa pegol; haemophilia A; polyethylene glycol; prophylaxis.

MeSH terms

  • Child
  • Factor VIII* / therapeutic use
  • Hemophilia A* / drug therapy
  • Humans
  • Infant, Newborn
  • Male
  • Polyethylene Glycols / therapeutic use
  • Treatment Outcome


  • BAY 94-9027
  • Polyethylene Glycols
  • Factor VIII

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