Study Shows C1-Esterase Inhibitor Concentrate is Safe and Consistently Effective for Long-Term Treatment of Hereditary Angioedema Attacks at Any Body Location

BOSTON, Nov. 5, 2011 /PRNewswire/ -- C1-esterase inhibitor (C1-INH) concentrate at 20 U/kg is a safe and effective therapy for the long-term treatment of successive acute swelling attacks at any body location in patients with hereditary angioedema (HAE), a rare and serious genetic disorder, according to final data presented at the 2011 American College of Allergy, Asthma & Immunology (ACAAI) Annual Meeting. Additional data presented at the meeting confirms that C1-INH concentrate provided consistent and reliable treatment response in patients treated for multiple successive HAE attacks at any body location.

The final results from the prospective, open label International Multi-center Prospective Angioedema C1-Inhibitor Trial (I.M.P.A.C.T. 2) with C1-INH concentrate showed a median time to the onset of symptom relief of 0.46 hours which was similar for all types of attacks, including laryngeal, abdominal, peripheral and facial. The median time for complete resolution was 15.5 hours.

"The final I.M.P.A.C.T. 2 results provide conclusive clinical evidence that C1-INH replacement therapy should be considered the first-line therapy in the on-demand treatment of acute swelling attacks of hereditary angioedema," said Timothy J. Craig, D.O., Professor of Medicine and Pediatrics at Penn State University in Hershey, PA.  "These compelling data reflect the outcomes of 1,085 HAE attacks, the largest number of HAE attacks treated in a prospective study, and show that C1-INH concentrate is highly and consistently effective, safe and well-tolerated in rapidly relieving symptoms of HAE at many different regions of the body, with no rebound effects. In fact, 99 percent of all attacks were successfully treated with a single dose of 20U/kg."

The effect of repeated treatment on the efficacy of C1-INH was also assessed in an analysis of 18 patients who were treated for at least 15 attacks. Results showed that the extent of previous use of C1-INH concentrate had no effect on the time between attacks treated with C1-INH concentrate, the time to onset of symptom relief or the time to complete resolution.

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, abdomen, larynx and extremities. 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.  

For further information about HAE, please visit the website of the International Patient Organization for C1-Inhibitor Deficiencies, www.HAEI.org and the disease information website www.allabouthae.com.

About I.M.P.A.C.T. 1

I.M.P.A.C.T. 1 was a study of 124 HAE patients with acute, moderate or severe abdominal or facial attacks. C1-INH concentrate was administered at two different doses and compared with placebo. The main study endpoints were time to onset of symptom relief from HAE attacks, proportion of subjects with worsening clinical HAE symptoms and safety.  

The I.M.P.A.C.T. 1 study found that C1-inhibitor concentrate (C1-INH) is effective and safe in rapidly treating acute abdominal and facial skin swellings in adults and adolescents with HAE.  The study found that the median time to symptom relief was 30 minutes after receiving C1-INH compared with 1.5 hours with a placebo.

About I.M.P.A.C.T. 2

Findings of I.M.P.A.C.T. 2 were based on treatment with 20 U/kg bodyweight of C1-INH in 1,085 episodes of HAE attacks at any body location in 57 patients. The main study end-points were time to onset of symptom relief, time to complete resolution of all symptoms and safety. No drug-related serious adverse events were reported, nor were any rebound effects observed following C1-INH administration.

About CSL Behring

CSL Behring is a global leader in the plasma protein biotherapeutics industry. Passionate about improving the quality of patients' lives, CSL Behring manufactures and markets a range of safe and effective plasma-derived and recombinant products and related services. The company's therapies are used in the treatment of immune deficiency disorders, hereditary angioedema, hemophilia, von Willebrand disease, other bleeding disorders and inherited emphysema. Other products are used for the prevention of hemolytic diseases in the newborn, in cardiac surgery, organ transplantation and in the treatment of burns. The company also operates one of the world's largest plasma collection networks, CSL Plasma. CSL Behring is a subsidiary of CSL Limited, a biopharmaceutical company with headquarters in Melbourne, Australia. For more information, visit www.cslbehring.com.

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CSL Behring
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