Horizon's Poor Primary Care Performance Overshadows River Vision Buy

A poor first quarter for Dublin, Ireland-headquartered Horizon Pharma PLC's primary care business leading it to lower its full-year revenue guidance and causing a 35% share price plunge on May 8 has overshadowed its acquisition of River Vision Development Corp., a deal which is expected to boost its fast-growing orphan drug segment, and a strong performance of its orphan drugs portfolio.

The buy allows Horizon to get its hands on River's key pipeline product teprotumumab (RV001) for a rare inflammatory eye disorder. It builds on the purchase of of Raptor...