A New Risk-Based Scoring Approach to Individualize Prophylaxis in Patients with Hemophilia A: Results from the PREDICT Study

Introduction: There is currently no consensus on optimal prophylaxis with clotting factor concentrates in hemophilia A. With or without pharmacokinetic data, prophylaxis regimens are often based on local practice and patient-specific factors, including bleeding history and activity level. The PREDICT study evaluated a baseline clinical risk score, based on phenotypic and biologic variables, to guide prophylactic regimen selection when switching from standard half-life (SHL) factor VIII concentrates to damoctocog alfa pegol. Methods: This multicenter, prospective study enrolled 21 participants aged ≥ 12 years with congenital hemophilia A of any severity who had received SHL prophylaxis for ≥ 6 months. Each participant was assigned a risk score (low, medium, high) based on five predefined variables: bleeding phenotype, treatment frequency, active target joints, von Willebrand factor levels, and physical activity. All participants initiated damoctocog alfa pegol at twice-weekly dosing for 4 weeks, after which regimens were individualized: 2×/week for high risk, every 5 days (Q5D) for medium risk, and Q5D for 4 weeks followed by less frequent dosing for low risk participants. A favorable outcome was defined as a reduction in annualized bleeding rate (ABR) and/or infusion frequency compared with previous SHL prophylaxis. Results: Among 17 evaluable participants, 12 (70.6%) achieved a favorable outcome for treated and untreated bleeds. All 12 had improved ABR, and 11 required fewer infusions. When considering only treated bleeds, 77% achieved a favorable outcome. Mean ABR decreased by 8.01 and infusion frequency reduced by a mean of 6.9 infusions/month. The 25 active target joints identified at baseline were reduced by 96% at study completion. Conclusions: The PREDICT risk-based scoring system-guided individualized prophylaxis with damoctocog alfa pegol, yielding improved bleeding outcomes and reduced treatment burden in most participants. These findings support the use of structured, risk-adapted approaches to personalize prophylaxis when transitioning from SHL to damoctocog alfa pegol. Trial Registration: NCT05036278.