New data on Soliris for PNH treatment to be presented at ASH Annual Meeting

Alexion Pharmaceuticals, Inc. (Nasdaq: ALXN) today announced that researchers are scheduled to present new data relating to Soliris^® (eculizumab) as a treatment for patients with paroxysmal nocturnal hemoglobinuria (PNH) during the 52nd Annual Meeting of the American Society of Hematology (ASH), to be held December 4 - 7, 2010 at the Orange County Convention Center in Orlando. New data regarding Alexion's anti-CD200 antibody samalizumab will also be presented at the ASH meeting. Abstracts summarizing these presentations were published today on the ASH web site and can be accessed using the links provided below.

“Long Term Safety and Efficacy of Sustained Eculizumab Treatment In Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH)”

Soliris and PNH

The following abstract will be presented in an oral session on Monday, December 6, 2010 at 3:15 p.m. EST:

"Long Term Treatment with Eculizumab In Paroxysmal Nocturnal Hemoglobinuria (PNH): Sustained Efficacy and Improved Survival," Kelly, et al.

Abstract: http://ash.confex.com/ash/2010/webprogram/Paper29252.html.

The following abstract will be presented in a poster session on Saturday, December 4, 2010 from 5:30 - 7:30 p.m., Eastern Standard Time (EST):

"Evaluation of Paroxysmal Nocturnal Hemoglobinuria Disease Burden: The Patient's Perspective. A Report from the International PNH Registry," Muus, et al.

Abstract: http://ash.confex.com/ash/2010/webprogram/Paper33464.html.

The following abstract will be presented in a poster session on Sunday, December 5, 2010 from 6:00 - 8:00 p.m. EST:

"Use of Blood Transfusions in Paroxysmal Nocturnal Hemoglobinuria Patients with and without Aplastic Anemia Enrolled in the Global PNH Registry," Schrezenmeier, et al.

Abstract: http://ash.confex.com/ash/2010/webprogram/Paper34068.html.

The following abstracts will be presented in a poster session on Monday, December 6, 2010 from 6:00 - 8:00 p.m. EST:

"Long Term Safety and Efficacy of Sustained Eculizumab Treatment In Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH)," Brodsky, et al.

Abstract: http://ash.confex.com/ash/2010/webprogram/Paper31763.html.

"Association Between Elevated Hemolysis at Diagnosis and Early Mortality and Risk of Thrombosis In Paroxysmal Nocturnal Hemoglobinuria (PNH) Patients with Cytopenia," Kim, et al.

Abstract: http://ash.confex.com/ash/2010/webprogram/Paper32764.html.

Samalizumab

During the meeting, researchers are also scheduled to present results from a Phase 1 study investigating samalizumab, an anti-CD200 antibody developed by Alexion, in patients with treatment refractory chronic lymphocytic leukemia or multiple myeloma.

The following abstract will be presented in a poster session on Sunday, December 5, 2010 from 6:00 - 8:00 p.m. EST:

"First-in-Human Phase I Dose Escalation Study of a Humanized Anti-CD200 Antibody (Samalizumab) in Patients with Advanced Stage B cell Chronic Lymphocytic Leukemia (B-CLL) or Multiple Myeloma (MM)," Mahadevan, et al.

Abstract: http://ash.confex.com/ash/2010/webprogram/Paper30391.html.