In two separate deals to strengthen its long-term prospects in ophthalmology and central nervous system therapeutic areas, Biogen has entered into research alliances with the University of Pennsylvania (UPenn) and its spinoff Regenxbio. Both agreements involved licensing of certain adeno-associated virus (AAV) vectors and while the collaboration with UPenn focused on ocular, skeletal muscle and nervous system disorders and was valued around US$2 B, the deal with Regenxbio centred on two rare ocular disorders with no disclosure of financial terms.