Dyax announces first Phase 3 trial results of KALBITOR for acute HAE

Dyax Corp. (NASDAQ: DYAX) announced today that results from EDEMA3^®, the Company's first Phase 3 trial evaluating KALBITOR^® (ecallantide) for the treatment of acute attacks of hereditary angioedema (HAE), were published in the August issue of The New England Journal of Medicine. KALBITOR, discovered and developed by Dyax, is available in the United States for the treatment of acute attacks of HAE in patients 16 years of age and older.

“The KALBITOR clinical program, including EDEMA3 and EDEMA4®, supports the treatment benefit of KALBITOR for HAE acute attacks”

EDEMA3 was the first of two Phase 3 trials evaluating KALBITOR for the treatment of acute HAE attacks. Results showed a statistically significant improvement of HAE attack symptoms with KALBITOR treatment versus placebo.

"The KALBITOR clinical program, including EDEMA3 and EDEMA4^®, supports the treatment benefit of KALBITOR for HAE acute attacks," said H. Henry Li, MD, an author and Director of Immunology at the Institute for Asthma & Allergy in Wheaton, MD. "Moreover, the publication of these data will enhance understanding among the physician community about the value of KALBITOR's unique mechanism of action, as a selective plasma kallikrein inhibitor, in resolving acute HAE symptoms."

The overall safety profile of KALBITOR observed in EDEMA3 was similar to that of placebo. The most common adverse events occurring more often in KALBITOR-treated patients versus placebo were mild or moderate and included: headache, diarrhea, pyrexia and nasal congestion. Treatment-related adverse events and serious adverse events occurred at a similar proportion in both the KALBITOR- and placebo-treated groups.

EDEMA3 was a 72-patient, double-blind, placebo-controlled trial randomized 1:1 to receive a 30 mg subcutaneous dose of KALBITOR or placebo. Patients were observed for at least 4 hours after KALBITOR was administered. Symptoms were assessed every 15 minutes for the first two hours, every 30 minutes for the next two hours, and again at 24 hours.

EDEMA3 was the first study to assess treatment response with two HAE-specific patient-reported outcomes measures, which were developed and validated by Dyax. Prior to the EDEMA3 trial, there was no validated instrument to assess HAE symptom complexes. The Mean Symptom Complex Severity (MSCS) score provides a point-in-time measure of individual symptoms that accounts for symptom location and severity of the attack using a score from 0 to 3>

The primary endpoint was the TOS at 4 hours after dosing with KALBITOR or placebo. The principal secondary endpoint was the change from baseline in MSCS at 4 hours. At 4 hours post treatment, statistically significant improvement of symptoms was demonstrated for KALBITOR versus placebo, as measured by both the median TOS>