Merck Acquires Development and Commercialization Rights to Investigational mTOR Inhibitor Ridaforolimus from ARIAD Pharmaceuticals, Inc.

Whitehouse Station, N.J. - Merck (NYSE:MRK) today announced that it has restructured its co-development and co-commercialization agreement with ARIAD Pharmaceuticals, Inc. for ridaforolimus, an investigational orally available mTOR inhibitor currently being evaluated for the treatment of multiple cancer types, to an exclusive license agreement.

Under the restructured agreement, Merck has acquired full control of the development and worldwide commercialization of ridaforolimus. ARIAD will receive a $50 million upfront fee and is eligible to receive milestone payments associated with regulatory filings and approvals of ridaforolimus in multiple cancer indications and achievement of significant sales thresholds. In lieu of the profit split on U.S. sales provided for in the previous agreement, ARIAD will now receive royalties on global net sales of ridaforolimus, and all sales will be booked by Merck. Merck will assume responsibility for all activities and has acquired decision rights on matters relating to the development, manufacturing and commercialization of ridaforolimus. The Investigational New Drug (IND) application will be transferred to Merck, and Merck will file the marketing application worldwide for any oncology indications and lead all interactions with regulatory agencies.

“This amended agreement positions Merck and ARIAD to maximize the therapeutic potential of ridaforolimus by evaluating its properties in multiple cancer types and furthers Merck’s commitment to oncology research and advancing the health of people suffering from cancer,” said Muna Bhanji, senior vice president and general manager, Oncology franchise at Merck.

About Merck
Today’s Merck is working to help the world be well. Through our medicines, vaccines, biologic therapies, and consumer and animal 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 health care through far-reaching programs that donate and deliver our products to the people who need them. Merck. Be Well. For more information, visit www.merck.com.

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 U.S. 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 2009 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).