Merck & Co. bids adieu to blockbuster osteoporosis drug Fosamax, which finally runs out patent protection, putting end Merck’s windfall $ 1.9 billion US market. Teva & Barr Laboratories launched the generic versions of Fosamax after receiving final approval from the US Food and Drug Administration and will jointly share 180-day market exclusivity. Under an agreement deal with Merck, Watson will launch an authorized generic to compete and share market space with Teva and Barr. Pfizer’s anti-cancer drug Camptosar worth over $ 500 million US sales is next to lose patent protection for its drug compound Irinotecan hydrochloride on February 20. In October 2007, Dabur Pharma received the tentative approval for generic Irinotecan from the US FDA.