The company's first product to reach the market, Soliris-which treats a rare, but life-threatening disease that basically destroys red blood cells-has been a success. Sales rose about 50% in the most recent quarter compared to the equivalent period in 2010. Soliris is the only drug treating the blood disease, which is called paroxysmal nocturnal hemoglobinuria, and Alexion is now exploring other uses for its compound in the hopes of expanding the market for the medication.

Meanwhile, Alexion acquired Taligen Therapeutics early this year as part of its efforts to expand and diversify its drug pipeline. That deal brought early-stage compounds for age-related macular degeneration. Alexion also purchased an investigational therapy from Orphatec Pharmaceuticals for a rare metabolic disease that affects newborns.