Economic and clinical impact of emicizumab in people with moderate and severe Hemophilia A in the US

Abstract Introduction: Emicizumab is a recombinant, humanized, bispecific, monoclonal antibody that has become the standard of care in hemophilia A prophylaxis. Adoption of emicizumab as standard of care was likely supported by its subcutaneous administration and consistent pharmacokinetics compared with FVIII. The objective of this analysis was to estimate the population-level impact of emicizumab on clinical and economic outcomes since its approval in the US in 2017 and the projected impact over the next ten years. Methods: A population impact model was used to evaluate outcomes associated with emicizumab market approval and uptake relative to a hypothetical scenario in which emicizumab is unavailable and only standard or extended half-life factor VIII replacement products and bypassing agents are available for prophylactic treatment. Model outcomes included the number of treated bleeds averted (including treated joint bleeds) and the number of arthroplasties prevented. The total direct and indirect costs associated with these avoided outcomes were estimated. Direct costs included healthcare costs associated with outpatient visits, emergency room visits, hospitalizations and the cost of breakthrough bleed treatment. Indirect costs included work productivity among people with hemophilia A or caregivers. Relevant model inputs, including costs, were derived from published sources, including randomized clinical trials, real-world studies and the US Centers for Disease Control and Prevention. Market share estimates were based on internal data and were assumed to remain constant when evaluating outcomes for the next ten years and assuming no additional therapies enter the market. Results: Among an estimated 15,107 people in the US with moderate or severe hemophilia A in 2016, use of emicizumab has resulted in an estimated cumulative total of 958,810 treated bleeds averted (including 699,931 treated joint bleeds averted) and 2002 arthroplasties prevented since its approval in 2017. These avoided outcomes prevented a total of $42.6B in direct and indirect costs to payers. Over the next ten years, emicizumab treatment was projected to result in an additional 1.9M treated bleeds averted (including 1.4M treated joint bleeds averted) and 3292 arthroplasties prevented, with $80.5B in total costs avoided. Conclusions: In this US population impact model, emicizumab significantly reduced both bleeding events and the economic burden of hemophilia A.