Merck & Co. swung to a fourth-quarter profit from a year-earlier loss that was weighed down by an asset write-down for a drug-research setback, while sales inched up 2%. The Whitehouse Station, N.J., drug maker issued a forecast for full-year 2012 results that leaves room for earnings growth, while sales are expected to be flat or down due to the impending loss of U.S. patent protection for its top-selling drug, the asthma and allergy treatment Singulair. The expected generic competition for Singulair after the patent expiration in August will put Merck in a position similar to that of competitors Pfizer Inc. and Eli Lilly & Co., which this week posted declining sales and earnings for the fourth quarter as a result of recent patent losses for top drugs.
