Alexion Pharmaceuticals, Inc. announced that its Board of Directors has appointed David L. Hallal as the Company's Chief Executive Officer (CEO), effective April 1, 2015. Mr. Hallal currently serves as Alexion's Chief Operating Officer (COO) and is a Director of the Board. He will succeed Leonard Bell, M.D., Chairman and CEO, who will retire as CEO and continue to serve as Chairman of the Board.

Dr. Bell was the principal founder of Alexion in 1992 and has served as CEO for the past 23 years. Mr. Hallal, 48, has more than 25 years of experience in the biopharmaceutical industry. Since joining Alexion in 2006 to initiate commercial operations, he has served in key leadership positions of increasing responsibility, including as the Company's first Chief Commercial Officer, and was appointed COO and to the Board of Directors in 2014.

Mr. Hallal has played a principal role in leading many of the Company's key growth initiatives, including the highly successful launches of Soliris (eculizumab) in PNH and aHUS and the building of Alexionâ s 50-country operating platform.