Biogen Buys Apellis for $5.6 Billion to Expand Kidney Drugs (3)

Biogen Inc. has agreed to acquire Apellis Pharmaceuticals Inc. for $5.6 billion, expanding its treatments in immunology and rare diseases in one of the company’s largest-ever acquisitions.

The Cambridge, Massachusetts-based biotech company will pay $41 a share for Apellis, more than double its closing price on Monday, Biogen said in a statement, confirming a Bloomberg News report. Apellis’ stock had declined 32% so far this year through Monday’s close.

Apellis shares soared 135% to $40.23 on Tuesday in New York, their largest jump ever. Biogen shares closed down 2.3%.

Biogen will gain two approved drugs in the deal. Apellis’ best-selling ...