PB0251 - Indirect comparison of prophylaxis efficacy between simoctocog alfa and efanesoctocog alfa in severe hemophilia A and their cost in the United States

Background: Replacement therapy with factor VIII (FVIII) concentrates remains the mainstay of prophylaxis in patients with severe haemophilia A (HA). The lack of head-to-head studies precludes direct comparison of efficacy between different FVIII.

Aims: We used matching adjusted indirect comparison (MAIC) to compare the efficacy of pharmacokinetic-guided, personalised prophylaxis with simoctocog alfa (Nuwiq®) against standard prophylaxis with efanesoctocog alfa (Altuviiio®) in patients with severe HA. We also compared the associated estimated cost of these regimens in the United States (US).

Methods: For the MAIC, baseline age and body weight were used to re-weight individual patient data from 65 subjects from the NuPreviq study (simoctocog alfa) to match the aggregate data of 133 subjects from group A of the XTEND-1 study (efanesoctocog alfa). Efficacy outcomes included total annualised bleeding rate (ABR), percentage of patients with zero bleeds (including treated and untreated bleeds), and weekly consumption of FVIII. Calculated annual costs included direct and indirect costs.

Results: After matching, the percentage of patients with zero bleeds and mean total ABR were similar between the 2 regimens (Figure 1). The mean weekly dose was significantly higher in patients treated with simoctocog alfa versus efanesoctocog alfa (98.3 IU/kg vs 52.2 IU/kg; p< 0.001). The median dosing interval in the NuPreviq study was 3.5 days; patients in the XTEND-1 study were treated once-weekly. Despite the higher dose, the annual estimated cost of treatment per patient with simoctocog alfa was 34% lower versus efanesoctocog alfa ($792,046 vs $1,116,488) (Figure 2). This difference was mainly driven by the cost of prophylaxis.

Conclusion(s): Prophylaxis with simoctocog alfa resulted in similar zero bleed rates and total ABR as with efanesoctocog alfa, albeit at a higher weekly dose. Despite this observed higher dosing, simoctocog alfa endured a lower cost burden than efanesoctocog alfa.