Overall, subjects on average received 1.4 injections per week throughout the study period. The efficacy of Cinryze directly correlated with the interval between injections where 1000 units every 2 to 4 days resulted in 1 attack for every 132 days of treatment compared to 1000 units every 6 to 7 days which resulted in 1 attack for every 46 days of treatment. No clinical characteristics predicted the response to prophylactic C1INH-nf, including historical attack frequency.At enrollment, 42 subjects (28.8 percent) were taking regular prophylactic androgens in an effort to prevent attacks of HAE. During the study, 23 subjects (54.8 percent) discontinued androgens, 6 subjects (14.3 percent) discontinued regular use and switched to as-needed use, 5 subjects (11.9 percent) reduced the androgen dose, and 8 subjects (19 percent) remained on the same dose. The median monthly attack rate in the 23 subjects who discontinued androgens went from 3 attacks per month while on androgens to 0 attacks per month when switched to prophylactic Cinryze. No subjects discontinued the study drug because of an adverse event. Eighty-six percent of treatment-emergent adverse events were of mild or moderate intensity. A total of 99 of 101 serious adverse events reported were considered not related to Cinryze, and 2 serious adverse events (musculoskeletal chest pain and major depression) were of unknown relationship. "The results of this study reinforce the efficacy and safety profile of Cinryze when used up to 2.6 years and the clinically relevant impact Cinryze can offer to people living with HAE who are experiencing recurrent attacks," commented Dr. Bruce L. Zuraw, professor of medicine and program director of the Allergy and Immunology Fellowship Program at the University of California at San Diego. "These data suggest that prophylactic Cinryze should be considered by the physician for any patient with hereditary angioedema who requires or desires prophylactic treatment." Study Design An open-label, multicenter extension study was performed to evaluate the safety and efficacy of Cinryze involving 146 subjects with HAE who were treated for up to 2.6 years in centers throughout the United States. Subjects were to be treated with Cinryze 1000 units every 3 to 7 days based on the decision of the investigator. The primary efficacy variable was the number of attacks of angioedema experienced. About Cinryze ® (C1 esterase inhibitor [human]) Cinryze is a highly purified, pasteurized and nanofiltered plasma-derived C1 esterase inhibitor product. In the U.S., Cinryze is approved by the FDA for routine prophylaxis against angioedema attacks in adolescent and adult patients with HAE. In the E.U., the product is approved by the EMA for the treatment and pre-procedure prevention of angioedema attacks in adults and adolescents with hereditary angioedema (HAE), and routine prevention of angioedema attacks in adults and adolescents with severe and recurrent attacks of hereditary angioedema (HAE), who are intolerant to or insufficiently protected by oral prevention treatments or patients who are inadequately managed with repeated acute treatment. Cinryze is for intravenous use only.