Alexion Pharmaceuticals, Inc. agreed to acquire remaining majority stake in Caelum Biosciences, Inc. from Fortress Biotech, Inc. and others for $500 million.

Alexion Pharmaceuticals, Inc. agreed to acquire Caelum Biosciences, Inc. from Fortress Biotech, Inc. (NasdaqCM:FBIO) and others for $500 million on September 28, 2021. Upon closing, Alexion will pay Caelum the agreed option exercise price of approximately $150 million, with the potential for additional payments of up to $350 million upon achievement of regulatory and commercial milestones. The transaction is expected to close on October 5, 2021.

Mark McElreath and James Sullivan of Alston & Bird LLP acted as the legal advisors to Caelum Biosciences.