Safety and Efficacy of Damoctocog Alfa Pegol in Previously Treated Children Aged 7 to < 12 Years With Severe Haemophilia A in the Phase 3, Open Label Alfa-PROTECT Main Study.

BACKGROUND

In the earlier PROTECT VIII Kids study (NCT01775618), damoctocog alfa pegol was efficacious for prevention and treatment of bleeds in children aged < 12 years with severe haemophilia A.

OBJECTIVE

Assess the safety of damoctocog alfa pegol, including hypersensitivity and loss of efficacy (LoE) due to an immune response to polyethylene glycol, in children aged 7 to < 12 years with severe haemophilia A.

METHODS

Alfa-PROTECT is a phase 3, multicentre, open-label, single-arm study (NCT05147662). Primary endpoint was the incidence of adverse events of special interest (AESI) leading to discontinuation during the first 4 exposure days.

RESULTS

Overall, 35 children enrolled; 32 completed the 6-month study, 21 (60%) reported ≥ 1 AE. Median (range) treatment duration was 182 (172-198) days. All AEs were mild/moderate; 3/35 children (8.6%) had study drug-related AEs. One (2.9%) LoE event was considered an AESI, and led to temporary treatment interruption. No AEs resulted in study drug discontinuation. The probability of < 5% of patients experiencing an AESI was 92.2%. Bleed protection was maintained with damoctocog alfa pegol prophylaxis.

CONCLUSIONS

These data confirm the safety profile of damoctocog alfa pegol in children aged 7 to < 12 years with severe haemophilia A. Secondary endpoints indicate treatment was efficacious.

TRIAL REGISTRATION: The Alfa-PROTECT trial is registered at ClinicalTrial.gov (NCT05147662).