C1-INH concentrate, an effective therapy to treat acute swelling attacks for HAE

CSL BehringNov 9 2009

Patients reported C1-esterase inhibitor (C1-INH) concentrate is an effective therapy in treating acute swelling attacks at any body location for HAE, a rare and serious genetic disorder, according to data presented today at the 2009 American College of Allergy, Asthma & Immunology (ACAAI) Annual Meeting. The results come from a self-reported survey of patients conducted in parallel with the ongoing, prospective, open label International Multi-center Prospective Angioedema C1-Inhibitor Trial (I.M.P.A.C.T. 2) for C1-INH concentrate. Of the patients surveyed, 98.3 percent reported satisfaction with the treatment, with 37 percent responding that without C1-INH they would have sought emergency treatment and 43 percent would have deferred any medical therapy.

Twenty-eight patients participated in the self-reported survey with responses collected via home computer or telephone voice response. Before the study, these patients reported an annual average of three emergency room visits and four hospital days due to acute attacks. Over 29 months, participants reported 384 attacks (261 abdominal, 71 extremities, eight facial, six genitourinary, 17 laryngeal, and 21 other) with a median of three per patient. C1-INH was used to treat approximately 71 percent of reported attacks. From the start of the attack to C1-INH dosing, the mean time was 12.1 hours (ranging from 0.0 to 189.8 hours) and the mean time from start of treatment to onset of symptom relief was 1.07 hours (ranging from 0.0 to 25.3 hours). The mean time to complete resolution was 18.4 hours (ranging from 1.22 to 471.7 hours).

"Recognizing an acute attack in its early stages is vital in successfully managing the disease," said Robyn J. Levy, M.D., of the Family Allergy & Asthma Center in Atlanta, GA, and the lead investigator of the study. "This survey shows that patients found C1-INH replacement therapy to be highly effective for the treatment of acute HAE attacks and without it some patients may have sought emergency treatment or deferred treatment altogether."

HAE is a genetic disorder caused by a deficiency of C1-INH and is inherited in an autosomal dominant manner. Symptoms of HAE include episodes of edema or swelling in the face and the abdomen. Patients who have abdominal attacks of HAE can experience episodes of severe pain, diarrhea, nausea, and vomiting caused by swelling of the intestinal wall. HAE attacks that involve the face can cause painful distortion and painful swelling. Diagnosis of HAE requires a blood test to confirm low or abnormal levels of C1-INH. There are estimates of 6,000 to 10,000 or more people with HAE in the U.S.

As part of the same survey, patients could also complete a health-related quality of life (HRQoL) section to compare their opinions about HAE treatment before and after C1-INH. The SF-12 generic measure of health status was supplemented with questions about the effects of C1-INH. Eighteen patients provided HRQoL feedback on 55 attacks with more than 57 percent of respondents reporting very good or excellent general health and 98.1 percent indicating few or no physical health-related limitations on activities. Three-quarters reported no or little pain interference with work and life. About two-thirds reported a positive change in outlook and "much better" feeling of security about treating future attacks.