Alexion Pharma International Sàrl, a subsidiary of Alexion Pharmaceuticals, Inc. (Nasdaq:ALXN), today announced that the U.S. Food and Drug Administration (FDA) has granted a Breakthrough Therapy designation to cyclic pyranopterin monophosphate (cPMP, or ALXN1101), an enzyme co-factor replacement therapy for the treatment of patients with molybdenum cofactor deficiency (MoCD) type A, a severe and life-threatening, ultra-rare, genetic metabolic disorder that causes catastrophic and irreversible neurologic damage within the first weeks of life. According to the FDA, a Breakthrough Therapy designation is designed to expedite the development of a drug to treat a serious or life-threatening disease when preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints. The Breakthrough Therapy designation is part of the FDA Safety and Innovation Act (FDASIA) of 2012. 1 “In designating cPMP as a Breakthrough Therapy, the FDA recognizes the life-threatening nature of MoCD Type A, the positive early clinical results associated with cPMP, and the lack of any effective treatment options for infants born with this devastating disease,” said Martin Mackay, Ph.D., Executive Vice President, Global Head of R&D at Alexion. “ALXN1101 is an innovative approach to the treatment of MoCD Type A, as it targets an essential step in the pathophysiology of the disease and the underlying cause of the disease by replacing the naturally occurring cPMP molecule, which is lacking in patients with MoCD Type A.” Alexion looks forward to working closely with the FDA and obtaining FDA guidance on the subsequent development of ALXN1101 for the treatment of patients with MoCD Type A, including obtaining advice on generating evidence needed to support approval of the drug in an efficient manner. Alexion has initiated a natural history study in patients with MoCD Type A and has also completed dosing with the synthetic cPMP in a study in healthy volunteers.