Merck Provides Update on Development Program for Suvorexant, an Investigational Orexin Receptor Antagonist for the Treatment of

Merck Provides Update on Development Program for Suvorexant, an Investigational Orexin Receptor Antagonist for the Treatment of Insomnia

Company Confirms Plans to File NDA for Suvorexant in 2012

WHITEHOUSE STATION, N.J., Feb. 6, 2012 -- Merck, known as MSD outside the United States and Canada, today provided an update on the development program for suvorexant, the company's investigational orexin receptor antagonist, which, if approved, will be a new mechanism for the treatment of insomnia. The two pivotal Phase III efficacy trials for suvorexant have been completed and, based on the positive results of these studies, Merck plans to file a New Drug Application (NDA) for suvorexant with the U.S. Food and Drug Administration (FDA) in 2012.

Both Phase III studies were multicenter, randomized, double-blind, placebo-controlled clinical trials that evaluated suvorexant compared to placebo in adult patients ages 18 years and older. The primary endpoint was change from baseline in subjective total sleep time and time to sleep onset, wake time after persistent sleep onset, and latency to onset of persistent sleep at one and three months. Merck plans to submit these data for presentation at major medical meetings later this year.

Suvorexant is one of the five major U.S. filings Merck anticipates for 2012 and 2013.

"Suvorexant selectively targets an important pathway involved in helping to promote sleep and, if approved, will be a new, first-in-class treatment for patients with insomnia," said Peter S. Kim, president, Merck Research Laboratories. "We are enthusiastic about the potential of this investigational medicine, and look forward to sharing the results from these studies with the medical community."

About Merck
Today's Merck is a global healthcare leader working to help the world be well. Merck is known as MSD outside the United States and Canada. Through our prescription medicines, vaccines, biologic therapies, and consumer care and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to healthcare through far-reaching policies, programs and partnerships. For more information, visit www.merck.com and connect with us on Twitter, Facebook and YouTube.

Forward-Looking Statement
This news release includes "forward-looking statements" within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. Such statements may include, but are not limited to, statements about the benefits of the merger between Merck and Schering-Plough, including future financial and operating results, the combined company's plans, objectives, expectations and intentions and other statements that are not historical facts. Such statements are based upon the current beliefs and expectations of Merck's management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forward-looking statements.

The following factors, among others, could cause actual results to differ from those set forth in the forward-looking statements: the possibility that the expected synergies from the merger of Merck and Schering-Plough will not be realized, or will not be realized within the expected time period; the impact of pharmaceutical industry regulation and health care legislation; the risk that the businesses will not be integrated successfully; disruption from the merger making it more difficult to maintain business and operational relationships; Merck's ability to accurately predict future market conditions; dependence on the effectiveness of Merck's patents and other protections for innovative products; the risk of new and changing regulation and health policies in the United States and internationally and the exposure to litigation and/or regulatory actions.

Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in Merck's 2010 Annual Report on Form 10-K and the company's other filings with the Securities and Exchange Commission (SEC) available at the SEC's Internet site (www.sec.gov).