Perrigo, Royalty Pharma deal

Perrigo will divest its royalty stream rights for multiple sclerosis drug Tysabri natalizumab to Royalty Pharma for $2.2 billion up front. Biogen Inc. (NASDAQ:BIIB, Cambridge, Mass.) markets the humanized mAb against integrin alpha(4). Perrigo is also eligible for up to $650 million in milestones from Royalty Pharma.

Perrigo gained the royalty rights through its acquisition of Elan Corp. plc in 2013. Prior to Perrigo's deal with Elan, Royalty Pharma ended a hostile bid to acquire Elan. Biogen acquired Tysabri from Elan in 2013. The deal stipulated that Elan was entitled to 18% royalties on worldwide Tysabri sales up to $2 billion and 25% royalties for sales over $2 billion (see BioCentury, Feb. 11, 2013 & Aug. 5, 2013)...