Horizon Pharma Public Limited Company, a biopharmaceutical company, engages in identifying, developing, acquiring, and commercializing medicines for the treatment of orphan diseases, arthritis, pain, and inflammation and inflammatory diseases in the United States and internationally. The company's marketed medicine portfolio consists of ACTIMMUNE for the treatment of chronic granulomatous disease and malignant osteopetrosis; RAVICTI and BUPHENYL/AMMONAPS to treat urea cycle disorders; PROCYSBI for the treatment of nephropathic cystinosis; QUINSAIR for the treatment of chronic pulmonary infections due to pseudomonas aeruginosa in cystic fibrosis patients; and KRYSTEXXA to treat chronic refractory gout. Its products also include RAYOS/LODOTRA for the treatment of rheumatoid arthritis, polymyalgia rheumatic, systemic lupus erythematosus, and multiple other indications; DUEXIS to treat signs and symptoms of osteoarthritis and rheumatoid arthritis; MIGERGOT for the treatment of vascular headache; PENNSAID 2% to treat pain of osteoarthritis of the knees; and VIMOVO for the treatment of signs and symptoms of osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. The company has collaboration agreements with Fox Chase Cancer Center to study ACTIMMUNE in combination with PD-1/PD-L1 inhibitors for use in the treatment of various forms of cancer; and Alliance for Lupus Research (ALR) to study the effect of RAYOS on the fatigue experienced by systemic lupus erythematosus (SLE) patients. Horizon Pharma Public Limited Company was founded in 2005 and is headquartered in Dublin, Ireland.