Background: To estimate health-related quality-of-life changes in patients with hereditary angioedema due to C1-inhibitor (C1-INH) deficiency who received subcutaneous C1-INH with recombinant hyaluronidase (rHuPH20) for attack prophylaxis in a randomized, double-blind, dose-ranging, cross-over study.
Methods: Patients with type I/II hereditary angioedema received 1000 U of C1-INH with 24,000 U of rHuPH20 or 2000 U of C1-INH with 48,000 U of rHuPH20 every 3-4 days for 8 weeks and then crossed over for another 8-week period. The study was terminated early as a precaution related to non-neutralizing antibodies to rHuPH20. The Angioedema Quality of Life questionnaire (AE-QoL) was administered at weeks 1 and 5 of both periods, and at 1 week after the second treatment period. Changes in AE-QoL scores were calculated over both treatment periods and within each treatment period for patients with ≥4 weeks of treatment.
Results: Forty-one patients had evaluable AE-QoL data, and 22 patients completed treatment. At screening, 43% of the patients were receiving intravenous C1-INH. A significant average AE-QoL total score decline (improvement) of -8.1 (95% confidence interval, -13.7 to -2.5) was observed from baseline to the end of the study, and significant AE-QoL score declines were observed in the Functioning, Fear/Shame, and Nutrition domains. Patients on 2000 U reported higher mean AE-QoL score declines in Functioning and Nutrition domains relative to the 1000 U dose. Overall, 43.9% of all the patients, 45.5% of the study completers, and 46.7% of the nonprophylaxis users at baseline on high treatment doses achieved a reduction in the AE-QoL total score of six points.
Conclusion: Despite early termination and prestudy prophylactic intravenous C1-INH use by 43% of the patients, improved AE-QoL scores were observed after ≤16 weeks of subcutaneous C1-INH-rHuPH20 prophylaxis.