Safety and efficacy of physician-supervised self-managed C1 inhibitor replacement therapy

Abstract

Background: C1 inhibitor (C1INH) has recently been approved in the USA for the treatment of acute attacks in hereditary angioedema (HAE) patients. The literature suggests that treatment with C1INH is most effective when administered early in an attack. Home infusion of C1INH allows for the earliest possible intervention since patients can initiate therapy at the first sign of symptoms.

Methods: We performed an observational, prospective study on 39 subjects with HAE utilizing two groups of patients: one receiving on-demand C1INH replacement therapy in a medical facility and the other self-managing on-demand C1INH replacement therapy in the home setting under the supervision of a treating physician. All subjects completed online questionnaires weekly for 8 weeks.

Results: There were statistically significant decreases in attack duration (p < 0.0001), pain medication use (p < 0.0001) and graded attack severity (p < 0.005) in the subjects who received C1INH in the home setting versus the clinic-based group. Attack frequency was similar between the groups. The home group experienced more frequent injection-related side effects; however, the clinic group noted more severe adverse events from C1INH.

Conclusion: Physician-supervised self-managed C1INH replacement therapy is a safe and effective treatment for patients with HAE with potential benefits in diminishing attack duration and attack severity.

Fig. 1

Severity of angioedema attacks in the clinic and home treatment groups (p < 0.005). Each attack is shown as a single black filled circle. Subjects graded each attack from 1 to 10 (1 being very mild and 10 being very severe). The mean severity for each group is shown as a straight line.

Fig. 2

Duration of angioedema attacks in the clinic and home treatment groups (p < 0.0001). Each attack is shown as a single black filled circle. The mean duration for each group is shown as a straight line.

Fig. 3

Number of prescription pain medications used per week in the clinic and home treatment groups (p < 0.0001). Each week is shown as a single black filled circle. Open circles represent 5 separate weeks, each requiring no pain medications. The mean weekly pain medication use for each group is shown as a straight line.