Horizon Therapeutics PLC is a specialty and generic drug manufacturing company. The company is focused on the discovery, development, and commercialization of medicines that address critical needs for people impacted by rare, autoimmune, and severe inflammatory diseases. The company has two reportable segments: orphan and inflammation. Orphan segment consists of medicines such as TEPEZZA, KRYSTEXXA, RAVICTI, PROCYSBI, ACTIMMUNE, UPLIZNA, BUPHENYL, and QUINSAIR. Inflammation segment consists of PENNSAID 2%, DUEXIS, RAYOS, and VIMOVO. It generates the vast majority of its revenue from the United States.