Complex sentence: T-Vec was created and initially developed by BioVex, Inc. under the brand OncoVEX GM-CSF; development was continued by Amgen, which acquired BioVex in 2011.
Split into simpler sentences: T-Vec was created and initially developed by BioVex, Inc. under the brand OncoVEX GM-CSF. Development was continued by Amgen, which acquired BioVex in 2011.