Just days after Alexion Pharmaceuticals Inc. said it completed enrollment in a pivotal trial of its cardiovascular drug, pexelizumab, ahead of schedule, the company priced a public offering to raise $66.9 million.

Cheshire, Conn.-based Alexion is selling 2.5 million shares of its common stock for $26.75 per share. Proceeds are expected to be used for general corporate purposes. Morgan Stanley & Co., of New York, is acting as underwriter for the offering.

Due to SEC quiet-period restrictions, the company was unable to comment. Its shares (NASDAQ:ALXN) lost 32 cents Friday to close at $27.

Last week, Alexion said it anticipates reporting results by the end of the year from its Phase III study evaluating pexelizumab in reducing mortality and myocardial infarction in patients following coronary bypass graft surgery. The study, initiated under an approved special protocol assessment, involves 4,250 patients and is expected to serve as the basis for a biologics license application.

Pexelizumab is a monoclonal antibody fragment aimed at inhibiting complement-mediated tissue damage that can occur during open heart surgery. The drug, partnered with Procter & Gamble Pharmaceuticals Inc., a unit of Cincinnati-based Procter & Gamble Co., also is in the middle of a Phase III study in patients experiencing myocardial infarction and being treated with primary percutaneous intervention.

Both pexelizumab and Alexion's second lead drug candidate, eculizumab, are known as C5 complement inhibitors, and are designed to selectively block the complement cascade to reduce inflammation.

The company is developing eculizumab, a monoclonal antibody targeted against complement activation in the immune system, on its own. The drug is in two Phase III trials in paroxysmal nocturnal hemoglobinuria. The first trial, which recently completed randomization in 85 PNH patients, will evaluate the efficacy of eculizumab based on the primary endpoints of hemoglobin stabilization and blood transfusion in hemolytic, transfusion-dependent patients over a six-month treatment period. Results of that trial are expected during the first quarter of next year.

In addition, Alexion began treating PHN patients in January in an open-label, companion study designed to include a six-month interim analysis, followed by six months of safety observation.

Alexion said it also has ongoing clinical trials of eculizumab in rheumatoid arthritis and membranous nephritis, and might consider the drug as a potential treatment for asthma. In June, the results of a study by Alexion and researchers at the Yale University School of Medicine and the Brigham and Women's Hospital were published in the Journal of Clinical Investigation, showing that a C5 inhibitor could reduce bronchial inflammation and airway constriction, both characteristics of asthma.

Alexion posted a net loss of $32.5 million, or $1.16 per share, for the three months prior to April 30. Cash, cash equivalents and marketable securities totaled about $226.6 million.

The company's last public financing came in July 2004, when it raised $85.25 million through the sale of 5.5 million shares priced at $15.50 per share.