Merck & Co., Inc. will not seek regulatory approval for taranabant, an investigational medicine, to treat obesity and is discontinuing its Phase III clinical development program for taranabant for obesity.

"Available Phase III data showed that both efficacy and adverse events were dose related, with greater efficacy and more adverse events in the higher doses. Therefore, after careful consideration, we determined that the overall profile of taranabant does not support further development for obesity," said John Amatruda, M.D., senior vice president and research head, diabetes and obesity, Merck Research Laboratories. "We thank the patients and investigators around the world who collaborated with us on the research program for taranabant and look forward to developing new medicines for obesity to address the significant medical need posed by this disease."

About Merck

Merck & Co., Inc. is a global research-driven pharmaceutical company dedicated to putting patients first. Established in 1891, Merck currently discovers, develops, manufactures and markets vaccines and medicines to address unmet medical needs. The Company devotes extensive efforts to increase access to medicines through far-reaching programs that not only donate Merck medicines but help deliver them to the people who need them. Merck also publishes unbiased health information as a not-for-profit service. For more information, visit www.merck.com.

Forward looking statement

This press release contains "forward-looking statements" as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements are based on management's current expectations and involve risks and uncertainties, which may cause results to differ materially from those set forth in the statements. The forward-looking statements may include statements regarding product development, product potential or financial performance. No forward-looking statement can be guaranteed and actual results may differ materially from those projected. Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events, or otherwise. Forward-looking statements in this press release should be evaluated together with the many uncertainties that affect Merck's business, particularly those mentioned in the risk factors and cautionary statements in Item 1A of Merck's Form 10-K for the year ended Dec. 31, 2007, and in any risk factors or cautionary statements contained in the Company's periodic reports on Form 10-Q or current reports on Form 8-K, which the Company incorporates by reference.

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