AstraZeneca PLC A merger between Astra of Sweden and Zeneca of the United Kingdom formed AstraZeneca in 1999. The firm sells branded drugs across a number of major therapeutic areas, including oncology (over 40% of total revenue), cardiovascular, renal, and metabolic (over 20%), rare disease (16%), and respiratory and immunology (15%). The majority of sales comes from international markets, with the United States representing close to one-third of its sales.