Alexion Pharmaceuticals Inc has commenced enrollment in the pivotal Phase III clinical trial of pexelizumab in approximately 3,000 patients undergoing coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB).

The Phase III program, if successful, is expected to be sufficient to support registration of the drug with the U.S. Food and Drug Administration. The trial, to be conducted by Alexion and Procter & Gamble Pharmaceuticals, its partner in the development of pexelizumab, is referred to as "Pexelizumab for Reduction in Infarction and Mortality in Coronary Artery Bypass Graft Surgery," or "PRIMO-CABG."

"The commencement of the first pexelizumab pivotal trial is an important development and corporate milestone for Alexion," stated Leonard Bell, President and Chief Executive Officer of Alexion. "Initiation of this trial brings us closer to realizing the therapeutic potential of pexelizumab in CABG patients, while at the same time we continue parallel development of pexelizumab in patients suffering acute myocardial infarction."

In this randomized, placebo-controlled multi-center trial, approximately 3,000 patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass will be treated with either placebo or pexelizumab 2.0 mg/kg bolus followed by a continuous 24 hour infusion. The Phase III trial will assess the safety and efficacy of pexelizumab in reducing the combined incidence of death and myocardial infarction in this patient population.

According to the American Heart Association, approximately 550,000 cardiopulmonary pulmonary bypass procedures were performed in the U.S. in 1998.