Dyax Corporation and Genzyme Corporation announced positive initial results from their phase II, double-blind placebo-controlled clinical trial of DX-88 for the treatment of hereditary angioedema (HAE).

The trial, referred to as EDEMA1 (Evaluating DX-88's Effects on Mitigating Angioedema), was designed to assess the efficacy and safety of DX-88 in the treatment of all forms of acute attacks of HAE, including peripheral, abdominal and laryngeal attacks.

The trial met its primary endpoint, significant improvement in the symptoms of acute attacks of HAE, a debilitating acute inflammatory condition for which there is no approved treatment in the US, within four hours of treatment, and demonstrated a statistically significant effect of the drug. The safety profile of DX-88 in the trial was similar to placebo.

"We are pleased with these positive results," stated Henry E. Blair, chairman, president and CEO of Dyax Corp. "The data provides validation of the positive effect of DX-88 in HAE patients. To recognize the promise that DX-88 holds for improving the quality of life of HAE patients is a tremendous feeling. The EDEMA1 results represent a major accomplishment for this programme and for Dyax, and are a testament to the power of using targeted small proteins as novel therapeutics," he added.

Dr. Anthony Williams, senior vice president of Medical Affairs and Clinical Operations for Dyax added, "We are now continuing patient treatment in our open label repeat dosing EDEMA2 trial, and are also expanding the number of trial sites. To date in human studies involving DX-88, over 140 doses have been administered in over 105 patients. With positive safety and efficacy data in hand, we remain hopeful that the EDEMA1 results, in conjunction with cumulative data from EDEMA2, may be adequate for potential regulatory filings with both the FDA and EMEA. We look forward to further discussions with the agencies to determine remaining requirements to permit those filings."

DX-88 has orphan drug designation in the United States and Europe for the treatment of HAE, a rare hereditary condition characterized by episodes of acute swelling and inflammation that can peripherally affect the extremities (hands, feet, face), the abdominal tract, the genitalia, and in life-threatening cases, the larynx. The prevalence of hereditary angioedema is believed to be between 1/10,000 and 1/50,000 people worldwide.

In Europe, there is one marketed product for HAE in some countries. This product is plasma derived C1-Inhibitor, which replaces the missing or dysfunctional protein in HAE patients. The C1-Inh product, however, carries the potential risk of blood-borne viruses and is a non-specific inhibitor of kallikrein.

DX-88, a specific and potent kallikrein inhibitor discovered at Dyax, is being developed for the treatment of HAE in a joint venture between Dyax Corp. and Genzyme Corporation.