Alexion's Soliris[R] Receives 2009 Prix Galien France for Most Innovative Drug for Rare Disease.

CHESHIRE, Conn. & PARIS -- Alexion Pharma France and Alexion Pharmaceuticals, Inc. (NASDAQ: ALXN) today received the 2009 Prix Galien France for Soliris([R]) (eculizumab) in the category of medicines for rare diseases. The award recognizes the scientific innovation represented by the complement-inhibition technology of Soliris, and the impact the drug is having on the lives of patients with paroxysmal nocturnal hemoglobinuria (PNH), an ultra-rare, debilitating and life-threatening blood disorder.

Soliris is a first-in-class terminal complement inhibitor that selectively blocks the formation of terminal complement, a component of the normal immune system. Patients with PNH lack naturally occurring proteins that ordinarily prevent terminal complement from causing the red blood cell destruction (hemolysis) that is central to the serious morbidities and mortality associated with PNH. The French award follows receipt last year by Alexion of the 2008 Prix Galien USA Award for Soliris as the Best Biotechnology Product with broad implications for future biomedical research.

"Alexion's employees in France and throughout Europe are gratified by this award and by the opportunity we have to improve the lives of patients with PNH," said Patrice Coissac, Senior Vice President of Alexion Pharmaceuticals, Inc. and President of Alexion International Sarl. "Alexion is committed to the objective that every patient with PNH who can benefit from Soliris will have access to Soliris, and each day, we are working with physicians and national healthcare authorities in Europe toward this goal."

About the Prix Galien

The Prix Galien (http://www.prixgalien.com/) was established in France in 1970 by French pharmacist Roland Mehl to recognize and promote significant advances in pharmaceutical research. The award is among the industry's highest accolades. The French award committee includes 17 eminent members from the scientific, medical, and academic communities of France.

Since its debut in France, the Prix Galien has been introduced in other countries of Europe, as well as in the U.S. and Canada. As in France, a prominent and independent panel of judges selects the winner, based on the innovative aspects and therapeutic advantages of the recipients. In addition, an International Prix Galien is selected from winners of the country awards every two years.

"We deeply appreciate this honor, which recognizes more than 15 years of basic and clinical research in the field of complement inhibition," said Leonard Bell, M.D., Chief Executive Officer of Alexion. "We are building on the success of Soliris by increasing our understanding of PNH and by evaluating the promise of complement inhibition for the treatment of patients with other ultra-rare and life-threatening disorders."

About PNH

Patients with PNH suffer from hemolysis (red blood cell destruction) which leads to thromboses (blood clots), disabling fatigue, anemia, impaired quality of life, pulmonary hypertension, shortness of breath, recurrent pain, kidney disease and intermittent episodes of dark-colored urine (hemoglobinuria). (1,2) PNH is an ultra-rare blood disorder that strikes people of all ages, with an average age of onset in the early 30s. (3) Approximately 10 percent of all patients first develop symptoms at 21 years of age or younger. (1) PNH develops without warning and can occur in men and women of all races, backgrounds and ages. PNH often goes unrecognized, with delays in diagnosis ranging from one to more than 10 years. (4) It is estimated that approximately one-third of patients with PNH do not survive more than five years from the time of diagnosis. (4) PNH has been identified more commonly among patients with disorders of the bone marrow, including aplastic anemia (AA) and myelodysplastic syndromes (MDS). (5,6,7) In patients with thrombosis of unknown origin, PNH may be an underlying cause. (1) More information on PNH is available at www.pnhsource.com.

About Soliris

Soliris has been approved by the U.S. Food and Drug Administration (March 2007), the European Commission (June 2007), Health Canada (January 2009) and Australia's Therapeutic Goods Administration (February 2009) as the first treatment for all patients with paroxysmal nocturnal hemoglobinuria (PNH), an ultra-rare, debilitating and life-threatening blood disorder defined by hemolysis, or the destruction of red blood cells. All four jurisdictions reviewed and approved their respective marketing applications for Soliris under their priority review or accelerated assessment procedures, and all four have designated Soliris as an orphan drug. Soliris is not approved for the treatment of transplant rejection. More information on Soliris is available at www.soliris.net.

Important Safety Information

Soliris is generally well tolerated. The most frequent adverse events observed in clinical studies were headache, nasopharyngitis (a runny nose), back pain and nausea. Treatment with Soliris should not alter anticoagulant management because the effect of withdrawal of anticoagulant therapy during Soliris treatment has not been established. The U.S. product label for Soliris also includes a boxed warning: "Soliris increases the risk of meningococcal infections. Vaccinate patients with a meningococcal vaccine at least two weeks prior to receiving the first dose of Soliris; revaccinate according to current medical guidelines for vaccine use. Monitor patients for early signs of meningococcal infections, evaluate immediately if infection is suspected, and treat with antibiotics if necessary." During clinical studies, two out of 196 vaccinated PNH patients treated with Soliris experienced a serious meningococcal infection. Prior to beginning Soliris therapy, all patients and their prescribing physicians are encouraged to enroll in the PNH Registry, which is part of a special risk-management program that involves initial and continuing education and long-term monitoring for detection of new safety findings.

About Alexion

Alexion Pharmaceuticals, Inc. is a biopharmaceutical company working to develop and deliver life-changing drug therapies for patients with serious and life-threatening medical conditions. Alexion is engaged in the discovery, development and commercialization of therapeutic products aimed at treating patients with a wide array of severe disease states, including hematologic and kidney diseases, transplant, cancer, and autoimmune disorders. Soliris is Alexion's first marketed product, approved in the U.S. and Europe in 2007, and Canada and Australia in 2009. Alexion is evaluating other potential indications for Soliris as well as other formulations of eculizumab for additional clinical indications, and is pursuing development of other antibody product candidates in early stages of development. This press release and further information about Alexion Pharmaceuticals, Inc. can be found at www.alexionpharma.com.

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This news release contains forward-looking statements, including statements related to potential health and medical benefits from Soliris. Forward-looking statements are subject to factors that may cause Alexion's results and plans to differ from those expected, including for example, decisions of regulatory authorities regarding marketing approval or material limitations on the marketing of Soliris, the possibility that results of clinical trials are not predictive of safety and efficacy results of Soliris in broader patient populations, the possibility that third party payers will decide not to reimburse for use of Soliris at acceptable levels or at all, and a variety of other risks set forth from time to time in Alexion's filings with the Securities and Exchange Commission, including but not limited to the risks discussed in Alexion's Quarterly Report on Form 10-Q for the period ended March 31, 2009. Alexion does not intend to update any of these forward-looking statements to reflect events or circumstances after the date hereof, except when a duty arises under law.

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2. Hill A, Richards S, Hillmen P. Recent developments in the understanding and management of paroxysmal nocturnal haemoglobinuria. Br J Haematol. 2007;137:181-92.

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4. Hillmen P, Lewis SM, Bessler M, Luzzatto L, Dacie JV. Natural history of paroxysmal nocturnal hemoglobinuria. N Engl J Med. 1995; 333:1253-1258.

5. Wang H, Chuhjo T, Yasue S, Omine M, Naka S. Clinical significance of a minor population of paroxysmal nocturnal hemoglobinuria-type cells in bone marrow failure syndrome. Blood. 2002;100 (12):3897-3902.

6. Iwanga M, Furukawa K, Amenomori T, et al. Paroxysmal nocturnal haemoglobinuria clones in patients with myelodysplastic syndromes. Br J Haematol. 1998;102 (2):465-474.

7. Maciejewski JP, Risitano AM, Sloand EM, et al. Relationship between bone marrow failure syndromes and the presence of glycophosphatidyl inositol-anchored protein-deficient clones. Br J Haematol. 2001;115:1015-1022.