AstraZeneca will exercise its option to buy out Merck’s interest in AZ’s non-proton pump inhibitor (non-PPI) products this year for $647 million. The products are Atacand, Lexxel, Plendil and Entocort, as well as several products in development. The option price reflects Merck’s share of projected pretax revenue for the products. The buy-out triggers AZ’s option to acquire Merck’s interest in AZ’s PPI products, including Nexium, in 2012 or later....