OBJECTIVES : To evaluate the cost-effectiveness of emicizumab prophylaxis compared to bypassing agent (BPA) on-demand treatments (aPCC or rFVII) for hemophilia A patients with inhibitors under the Korean healthcare system.

METHODS : A lifetime Markov model was developed with two health states: ‘Alive’ and ‘Death.’ The Alive state included two nested states: bleeding events represented by annualized bleeding rates (ABR) and arthroplasty. Based on the comparative effectiveness measured as the reduction rate of ABR between the two interventions from HAVEN 1 trial (87.0%, 95% CI: 72.3%-94.3%), and average ABR observed among Korean patients receiving BPA on-demand treatment (46.6 ABR), we calculated the expected number of treated bleeding among those with emicizumab prophylaxis (6.1 ABR). Costs were estimated using the Korea National Health Insurance claims data and the consultations with expert panels.

RESULTS : From the restricted societal perspective, the base-case analysis result showed that emicizumab prophylaxis was a dominant case, indicating better effectiveness and cost-saving compared to BPA on-demand treatment. When a patient starts receiving emicizumab prophylaxis from the age of 2, it is expected to avert about 800 treated bleeds and save 1.7 million US dollars over a lifetime as opposed to BPA on-demand treatments. Although the sensitivity analysis showed that the cost-effectiveness results were sensitive to the effectiveness of emicizumab and the number of ABR among patients treated with BPA on-demand therapy, the robustness of the base-case results was confirmed because the dominant status of emicizumab prophylaxis remained in most of the cases.

CONCLUSIONS : The incremental cost had minus value, and the incremental effectiveness was positive for nearly all scenarios considered, indicating that emicizumab prophylaxis is a robust cost-saving option.