Merck and ARIAD Announce EMAAccepts Marketing Authorization Application for Ridaforolimus

Merck and ARIAD Announce European Medicines Agency Accepts Marketing Authorization Application for Ridaforolimus, Investigational mTOR Inhibitor

Merck to Pay ARIAD $25 Million Milestone Payment for Acceptance of Filing

WHITEHOUSE STATION, N.J. & CAMBRIDGE, Mass., Aug. 18, 2011 -- Merck (NYSE:MRK), known outside the United States and Canada as MSD, and ARIAD Pharmaceuticals, Inc., (NASDAQ:ARIA), today announced that the European Medicines Agency (EMA) has completed its administrative validation process for the regulatory application for ridaforolimus, an investigational oral mTOR inhibitor developed for the treatment of metastatic soft-tissue or bone sarcomas in patients who had a favorable response to chemotherapy.

The completion of the marketing authorization application (MAA) validation process and acceptance for review now leads to the formal scientific review process by the EMA's Committee for Medicinal Products for Human Use. In addition to the EMA filing, Merck recently submitted a new drug application (NDA) for ridaforolimus to the U.S. Food and Drug Administration. Within the next 60 days, the FDA will determine whether it will accept Merck's application as submitted. As part of an exclusive license agreement with ARIAD, Merck is responsible for the development and worldwide commercialization of ridaforolimus in oncology. ARIAD intends to co-promote ridaforolimus in the United States.

"This acceptance of the EMA filing for review is an important milestone as we seek to bring forward a potential treatment option for patients with metastatic bone and soft tissue sarcomas," said Marty Duvall, senior vice president and general manager, oncology franchise, Merck Global Human Health.

"We are pleased with both the acceptance of the MAA in Europe and the timely filing of the NDA for ridaforolimus in the United States," said Harvey J. Berger, M.D., chairman and chief executive officer of ARIAD. "These regulatory initiatives underscore the importance of ridaforolimus for both ARIAD and the Merck oncology franchise, and we look forward to successful completion of the review process with both regulatory agencies."

About Sarcoma
 Sarcomas are a group of cancers of connective tissue of the body for which there are currently limited treatment options. Sarcomas can arise anywhere in the body and are divided into two main groups - bone tumors and soft-tissue sarcomas.

About Ridaforolimus
 Ridaforolimus is an investigational targeted and potent small-molecule inhibitor of the protein mTOR, a protein that acts as a central regulator of protein synthesis, cell proliferation, cell cycle progression and cell survival, integrating signals from proteins, such as PI3K, AKT and PTEN, known to be important to malignancy.

Merck's Commitment to Oncology
 Merck is committed to advancing all aspects of cancer care - prevention, treatment and supportive care. Through strong internal research capabilities, selective alliances and acquisitions, and enabling technologies, Merck is looking to lead in the discovery, development and delivery of anticancer therapies.

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.

About ARIAD
 ARIAD's vision is to transform the lives of cancer patients with breakthrough medicines. The Company's mission is to discover, develop and commercialize small-molecule drugs to treat cancer in patients with the greatest and most urgent unmet medical need - aggressive cancers where current therapies are inadequate. ARIAD's product candidate, ridaforolimus, is an investigational mTOR inhibitor being developed by Merck that has successfully completed a Phase 3 clinical trial in patients with soft-tissue and bone sarcomas and is being studied in multiple cancer indications. ARIAD's second internally discovered product candidate, ponatinib, is an investigational pan-BCR-ABL inhibitor in a pivotal Phase 2 clinical trial in patients with chronic myeloid leukemia and Ph+ acute lymphoblastic leukemia. For additional information, please visit http://www.ariad.com.