Shire plc and ViroPharma Inc. have entered into a merger agreement under which Shire will acquire all outstanding shares ViroPharma for approximately $4.2 billion. ViroPharma is a rare disease biopharmaceutical company, whose commercial product CINRYZE (C1 esterase inhibitor [human]), is a leading brand for the prophylactic treatment of Hereditary Angioedema (HAE).   Shire chief executive officer, Flemming Ornskov MD, said, “The acquisition of ViroPharma will immediately benefit Shire and ...