PSY89 - COSTS AND EFFECTS OF ON-DEMAND TREATMENT OF HEREDITARY ANGIOEDEMA: A PROSPECTIVE COHORT STUDY IN ITALY

Abstract

Hereditary angioedema due to complement C1-inhibitor deficiency (C1-INH-HAE) is a rare condition resulting in recurrent attacks of angioedema, which can cause temporary disability and be life-threatening. Clinical guidelines recommend the treatment of attacks at onset and several therapies for on-demand treatment are available in Italy. However, there is still little knowledge on different treatments’ behaviours, effectiveness and costs, which can affect coverage and reimbursement decisions. To explore treatment behaviours in a cohort of Italian patients with C1-INH-HAE and to estimate how effects and costs of treating attacks in routine practice differed across on-demand treatments. A one-year prospective cohort study on 167 patients was conducted at the Italian reference center for C1-INH-HAE. Attacks were treated with either icatibant, plasma derived C1 inhibitor (pdC1-INH) or supportive care. Survival analyses were carried out to evaluate treatment efficacy in reducing attack duration. Two-part models were used to estimate the direct costs of acute attacks. 133 of 167 patients (79.6%) reported 1,508 attacks during the study period, with mean incidence of 11 attacks per patient/year. Only 78.9% of attacks were treated. Both icatibant and pdC1-INH significantly reduced attack duration compared to no treatment (median times from onset 7, 10 and 47 hours respectively), but remission rates with icatibant were 31% faster compared to pdC1-INH (HR 1.31, 95%CI 1.14-1.51). However, observed treatment behaviours suggest patterns of sub-optimal dosing for pdC1-INH. The average cost per attack was €1,183 (SD €789) resulting in €1.58 million healthcare costs during the observation period (€11,912 per patient/year). The cost per attack was 54% more expensive with icatibant than pdC1-INH. Both icatibant and pdC1-INH significantly reduced attack duration compared to no treatment. Icatibant resulted to be more effective but more expensive. Treatment behaviours and sub-optimal dosing of pdC1-INH may account for the differences, but further research is needed to define their role.