2nd I.M.P.A.C.T. results in HAE attacks -- treat rapidly at onset of prodromal symptoms

The importance of recognizing prodromal symptoms and treating acute attacks of hereditary angioedema (HAE) at the onset of these symptoms was highlighted in a survey presented Sunday at the 2009 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting.

Nancy Burgess from Stinson Brand Innovation is attending the AAAAI conference and let us know about this paper on Sunday. HAE is an area we’ve been interested in for several years, and we’re interested in new medical treatments for this disease.

While symptoms of acute HAE attacks include episodes of edema or swelling in the hands and feet, the face, the abdomen, and/or the larynx, prodromal symptoms, which occur before an attack, are often non-specific and highly-variable, according to study findings. Treatment at the onset of these early symptoms can decrease morbidity and mortality associated with this rare and serious genetic disorder.

The prodromal symptoms companion survey, administered in parallel with the ongoing, prospective, open label International Multi-center Prospective Angioedema C1-Inhibitor Trial (I.M.P.A.C.T. 2), was designed to assess prodromal symptoms at the time of treatment of HAE attacks. Twenty-seven different patients were surveyed, representing 273 attacks, two-thirds of which were treated with C1 esterase inhibitor concentrate (C1-INH) at the time of their attack. The most commonly reported prodromal symptoms across all types of attacks were fatigue (27.83%), nausea (19.41%) and flu-like feelings (13.19%). Other prodromal symptoms included bowel movement change (7.33%), rumbling (5.86%), urticaria-like skin eruptions (6.54%), non-itchy rash (5.38%) and tingling (3.30%).

"To date there has been very little research into prodromal symptoms associated with HAE attacks," said Timothy J. Craig, D.O., Professor of Medicine and Pediatrics at Penn State University in Hershey, PA., and one of the study's investigators. "This survey underscores how important it is for patients to recognize the early symptoms of an HAE attack, as rapid treatment and resolution at this stage can reduce the impact the disease has on their quality of life."

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. 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.

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 time to the onset of symptom relief was 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. 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.

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, Japan, and several other countries.