C1-esterase inhibitor (C1-INH) concentrate is an effective, well-tolerated therapy that rapidly relieves acute swelling attacks at any body location in patients with hereditary angioedema (HAE), a rare and serious genetic disorder, according to data presented today at the 2009 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting. Interim results from the ongoing, prospective, open label International Multi-center Prospective Angioedema C1-Inhibitor Trial (I.M.P.A.C.T. 2), showed a median time to the onset of symptom relief of 16 minutes for laryngeal attacks, 23 minutes for abdominal attacks, 28 minutes for facial attacks and 31 minutes for peripheral attacks, such as attacks in the hands and feet. In total, 57 patients who experienced 640 HAE attacks in any body location were studied.
"This study shows that C1-INH replacement therapy is highly effective for the treatment of acute HAE attacks and it dramatically shortens attack duration," said Timothy J. Craig, D.O., Professor of Medicine and Pediatrics at Penn State University in Hershey, PA. "The I.M.P.A.C.T. 2 results underscore the versatility of C1-INH and validate the long-standing observation that this therapy effectively treats HAE attacks at many different regions of the body."
HAE is a genetic disorder affecting approximately 6,000 to 10,000 Americans and is caused by a deficiency of C1-INH, which is inherited in an autosomal dominant manner. Symptoms include episodes of edema or swelling in the hands and feet, the face, the abdomen, and/or the larynx. Patients who have abdominal attacks can experience episodes of severe pain, diarrhea, nausea, and vomiting caused by swelling of the intestinal wall. Attacks that involve the face and larynx can result in airway closure, asphyxiation, and, if untreated, death. Diagnosis of HAE requires a blood test to confirm low or abnormal levels of C1-INH. Hereditary angioedema attacks cause considerable morbidity and can be disruptive to patients’ daily life activities for several days, requiring trips to an emergency room and hospitalization. Recognizing an acute attack in its early stages is vital in successfully managing the disease.
In parallel with the I.M.P.A.C.T. 2 trial, a patient-driven automated survey was conducted with a subset of 27 patients to assess their views of HAE treatment before and after C1-INH therapy. Following treatment with C1-INH approximately two-thirds of patients reported "much better" physical and emotional health and change in outlook, while half of the patients reported feeling more secure in leaving home and returning to their normal daily activities.
"The patient survey findings highlight the unmet medical need in the HAE community and the positive impact that a treatment for acute attacks can have on quality on life," said Val Romberg, Senior Vice President of Research and Development at CSL Behring. "CSL Behring is excited about the prospect of meeting that need with C1-INH and is committed to improving the lives of patients with HAE and other rare disorders."
Currently, there are no approved therapies for acute attacks of HAE in North America. CSL Behring manufactures and sells C1-INH concentrate in Germany, Austria, Switzerland, and several other countries.
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 640 episodes of HAE attacks at any body location in 57 patients. The main study end-points were: time to onset of symptom relief; complete resolution of all symptoms, and safety.
The median times to complete resolution of all symptoms were reported as early as 8 hours for laryngeal attacks, 11 hours for abdominal, 24 hours for facial and 25 hours for peripheral attacks. No drug-related serious adverse events have been reported to date, nor were any rebound effects observed following C1-INH administration.
About the Patient Survey
Twenty-seven participating patients at seven sites reported 273 attacks over 16 months, with a median of 3.0/patient (range 1 to 70). Approximately 68 percent of the attacks were treated with C1-INH, 98.7 percent of which were reported by patients as responding satisfactorily. The average time from C1-INH administration to symptom relief onset was 1.3 hours and an average time to resolution was 1 day, 9 hours. According to the patients surveyed, if C1-INH was not available, 47 percent would have deferred medical therapy, 33 percent would have sought emergency care, and 7 percent would have self-treated with analgesics.
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, 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, ZLB Plasma. CSL Behring is a subsidiary of CSL Limited, a biopharmaceutical company with headquarters in Melbourne, Australia. For more information, visit www.cslbehring.com.
Sheila A. Burke, Director, Communications & Public Relations
Worldwide Commercial Operations