Key Takeaways Biogen has agreed to pay at least $1.15 billion for biotech firm Human Immunology Biosciences (HI-Bio) as it moves to increase its immunology portfolio. The deal includes the possibility of an additional$650 million in milestone payments. HI-Bio's lead asset treats rare kidney diseases. Biogen (BIIB) announced Wednesday it had purchased privately-held Human Immunology Biosciences (HI-Bio) for at least $1.15 billion to expand its reach into immunology medicines. The company said that the$1.15 ...