Amgen has entered into a definitive agreement to acquire BioVex Group, Inc., a privately held biotechnology company headquartered in Woburn, MA. BioVex is developing OncoVEX(GM-CSF), a novel oncolytic vaccine in Phase III development for the potential treatment of melanoma and head and neck cancer. BioVex will become a wholly owned subsidiary of Amgen. Amgen will pay as much as $1 billion, which includes $425 million in cash at closing and as much as $575 million in additional regulatory and sal...