FDA Advisory Committee Agrees That Clinical Data Support the Efficacy and Safety of Zostavax™, Merck's Investigational Vaccine for Shingles, in Adults Aged 60 and Older

Business Wire, Dec 15, 2005

WHITEHOUSE STATION, N.J. -- Merck & Co., Inc. announced today that the U.S. Food and Drug Administration's (FDA) Vaccines and Related Biological Products Advisory Committee agreed that the extensive data from clinical trials in more than 40,000 people support the efficacy and safety of ZOSTAVAX(TM) (zoster vaccine live (Oka/Merck)), the Company's investigational vaccine, to prevent shingles in adults aged 60 and over.

The Advisory Committee did not agree that the data presented were sufficient to support the efficacy and safety of ZOSTAVAX in adults aged 50 - 59 as the Company had proposed. The Advisory Committee also suggested areas for additional analysis. Merck plans to work with the FDA on these analyses as well as the design of Merck's already planned post-licensure studies.

The FDA is not bound by the committee's recommendation but takes its advice into consideration when reviewing investigational vaccines.

"Shingles can be a very painful disease that can lead to serious and long-lasting complications," said Peter S. Kim, Ph.D., president, Merck Research Laboratories. "We are pleased with today's outcome and look forward to working with the FDA as it continues its review of our application for this vaccine."

The company filed a Biologics License Application (BLA) with the FDA on April 25 for ZOSTAVAX to reduce the risk of shingles; to reduce the risk of postherpetic neuralgia, the persistent, often debilitating long-term nerve pain that is the most common complication of shingles; and to reduce the total burden of pain and discomfort caused by shingles.

In addition to the U.S. regulatory application, Merck has filed regulatory applications for ZOSTAVAX in several other world markets including the European Union, Canada and Australia.

Merck presented data from several studies conducted in more than 40,000 people, including data from the Phase III Shingles Prevention Study (SPS) of 38,500 adults age 60 and over. The SPS was a Department of Veterans Affairs (VA) study conducted in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH) and Merck at 22 U.S. research sites over a period of five years. Results from the SPS were published in the June 2 issue of The New England Journal of Medicine.

About Shingles and Postherpetic Neuralgia

Shingles is caused by the reactivation of latent varicella zoster virus -- the same virus that causes chickenpox. Shingles may first appear as abnormal skin sensations ranging from itching or tingling to severe pain on a single area of the body or face. It then usually progresses to a rash and fluid-filled blisters accompanied by pain in almost every case. The pain varies in intensity and duration. Shingles also can lead to severe complications, including long-term nerve pain (postherpetic neuralgia) that can follow an episode of shingles. This complication can last for months or even years after the rash has healed and can range from a tender, burning pain to a throbbing, stabbing pain.

Shingles can affect anyone who has had chickenpox -- more than 90 percent of adults in the United States -- and occurs most frequently in older adults. In fact, it is estimated that up to half of all people who reach age 85 will have developed shingles during their lifetime. A recent study estimated that up to 1 million cases of shingles occur every year in the United States. The number of shingles cases is expected to increase as the population ages.

ZOSTAVAX is one of three late-stage investigational vaccines at Merck. Yesterday, the same FDA Advisory Committee agreed that the clinical data supported the efficacy and safety of ROTATEQ, the Company's investigational vaccine to protect against rotavirus gastroenteritis. On Dec. 1, the Company submitted to the FDA its BLA for GARDASIL, the Company's investigational cervical cancer vaccine.

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.

Merck 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 cautionary statements in Item 1 of Merck's Form 10-K for the year ended Dec. 31, 2004, and in its periodic reports on Form 10-Q and Form 8-K, which the company incorporates by reference.