Safety, effectiveness, and impact on quality of life of self-administration with plasma-derived nanofiltered C1 inhibitor (Berinert®) in patients with hereditary angioedema: the SABHA study

Background: Hereditary angioedema with C1 inhibitor deficiency is a disabling, potentially fatal condition characterized by recurrent episodes of swelling. Self-treatment is recommended, in order to reduce admissions to the Emergency Room and the time between the onset of the attack and the treatment, resulting in a better treatment outcome and an improved quality of life (QoL). The purpose of this study is to assess the safety, tolerability, and effect on QoL of self-administration of pnf C1-INH for IV use (Berinert®). Methods: An observational, monocenter, prospective study was designed. Patients referring to a center for angioedema that attended two sessions of self-infusion training course in the period March 2014-July 2015 were enrolled in the study. The primary endpoint was to monitor the safety and feasibility of pnf C1-INH self-infusion. The secondary endpoint was to evaluate the effect of self-infusion on the QoL, by means of the HAE-QoL questionnaire and the need for access to Emergency Room for infusion of Berinert®. Patients' medical history data were collected upon the first visit and questionnaires were filled after each attack treated with Berinert® (diary and Treatment Satisfaction Questionnaire for Medication) and upon the first visit and the follow-ups (HAE-QoL). Results: Twenty patients were enrolled (median age = 42, IQR: 39-49; 60% females). Fifteen patients completed the study. A total of 189 attacks were recorded (annual median rate of 4 attacks/patient). Patients waited a median of 2 h (IQR: 1-4) before self-administration, and the resolution of the attack occurred after a median of 6 h (IQR: 4-11). Most attacks were abdominal (39%) and peripheral (22%). 92% of the attacks were treated through self-/caregiver-administration. In most attacks no side effects were reported. The number of attacks with side effects decreased over time, from 37% to 13%. Global satisfaction grew over time during the study period, reaching statistical significance over the first 6 months. The median total HAE-QoL score at baseline was 86 (IQR: 76-103) and improved in a non-significant manner throughout the study period. 8% of the attacks treated with Berinert® required ER admission/healthcare professional help in the study period, compared with 100% in the 3 years before enrollment (p < 0.0001). Conclusions: Self-administration of pnf C1-INH is safe, and increases patients' confidence in the treatment, showing also a trend towards an improvement in QoL. It reduces the need for ER admission/healthcare professionals help for the acute attacks, as well as the related costs.