Questcor Pharmaceuticals, Inc. was engaged in development, marketing and sale of prescription drugs. It operated as a biopharmaceutical company which focuses on the treatment of patients with serious, difficult-to-treat autoimmune and inflammatory disorders. The company's primary product was H.P. Acthar Gel, an injectable drug for the treatment of proteinuria in the nephrotic syndrome of the idiopathic type, or NS, the treatment of acute exacerbations of multiple sclerosis, or MS, in adults, the treatment of infantile spasms, or IS, in infants and children under two years of age, and the treatment of certain rheumatology related conditions, including the treatment of the rare and closely related neuromuscular disorders dermatomyositis and polymyositis. Questcor Pharmaceuticals was founded in September 1992 and was headquartered in Anaheim, CA.