Alexion Pharmaceuticals and Enobia Pharma have signed a definitive agreement under which Alexion will acquire 100% of the capital stock of Enobia. Enobia is a private biopharmaceutical company based in Montreal, Canada and Cambridge, Massachusetts, which is focused on the development of therapies to treat patients with ultra-rare and life-threatening genetic metabolic disorders.

Enobia's lead product candidate ENB-0040 (asfotase alfa), is a human recombinant targeted alkaline phosphatase enzyme-replacement therapy for patients suffering with hypophosphatasia (HPP), an ultra-rare, life-threatening, genetic metabolic disease for which there are no approved treatment options. Alexion will acquire full worldwide development and commercial rights to asfotase alfa. Asfotase alfa was awarded orphan drug designation in the U.S. and EU in 2008 and Fast Track status in the U.S. in 2009, and is currently in phase II clinical development.

"Enobia and our scientific collaborators have developed an elegant compound showing very promising clinical results to date," said Dr. Robert Heft, president and chief executive officer of Enobia. "Together with Alexion, we share a sharp focus on transforming the lives of patients with severe and ultra-rare disorders. The hypophosphatasia patient community will be well served by the experience and international scope of Alexion."

Alexion will acquire Enobia in an all-cash transaction. Under the terms of the agreement, Alexion has agreed to pay $610 million in cash upon consummation of the transaction, and up to $470 million in cash to be paid upon achievement of various regulatory and sales milestones. Alexion is not issuing equity in connection with the acquisition. The transaction is subject to customary conditions, including the expiration or termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act. The boards of both companies have approved the transaction and the companies currently anticipate that the transaction will be completed in the first quarter of 2012.

Alexion intends to finance the acquisition through cash on hand and $300 million of committed bank debt.