Today, the New England Journal of Medicine is publishing results from two Phase III studies of Merck's cervical cancer vaccine, GARDASIL [Quadrivalent Human Papillomavirus (Types 6, 11, 16, 18) Recombinant Vaccine]. In the first study, GARDASIL provided 100 percent protection against cervical, vaginal and vulvar diseases caused by the four HPV types GARDASIL is designed to protect against, HPV types 6, 11, 16, and 18. In the second study, GARDASIL provided 98 percent protection against advanced cervical pre-cancers caused by the two primary cancer-causing HPV types, HPV 16 and 18. These significant results, observed in 15- to 26-year-old women who were not infected with the relevant HPV types when they began the study, were sustained through an average of three years of participation in the trials, including an additional year of follow up since data were presented to the U.S. Food and Drug Administration (FDA) for approval of GARDASIL.

"In these two studies, GARDASIL demonstrated significant protection against serious HPV-related diseases, including high-grade cervical pre-cancers, in women not previously exposed to the relevant HPV types targeted by the vaccine," said Kevin Ault, M.D., associate professor, Division of Gynecologic Oncology, Department of Gynecology and Obstetrics, Emory University School of Medicine, Atlanta. "Widespread immunization of 11- to 26-year-old girls and women with GARDASIL, along with continued screening, will help decrease the burden of cervical cancer and other HPV-related diseases."

It is estimated that in 2007, cervical cancer will strike more than 11,000 women in the U.S. and nearly 500,000 women around the world. GARDASIL helps protect against the four HPV types - 6, 11, 16 and 18 - that cause the most disease, including 70 percent of cervical cancer cases and 90 percent of cases of genital warts. All four types cause a large number of "abnormal" Pap test results and low-grade cervical lesions.

"My fellow investigators around the world are proud of these data and their contribution to our understanding of the impact of GARDASIL on risk for development of cervical, vulvar, and vaginal diseases caused by HPV 6, 11, 16, and 18," said Eliav Barr, M.D., executive director of Biologics Clinical Research and head of the HPV Vaccine Program, Merck Research Laboratories. "In women not infected with the four HPV types targeted by GARDASIL, GARDASIL reduced cervical disease caused by the relevant HPV types. And, across the larger study population, GARDASIL also reduced the overall burden of cervical, vulvar, and vaginal HPV diseases caused by HPV types targeted by the vaccine and by other HPV types."

GARDASIL was approved by the FDA on June 8, 2006, and is recommended for use by girls and women ages 11 to 26 by the U.S. Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices. GARDASIL is indicated for the prevention of HPV types 16- and 18- related cervical cancer, non-invasive cervical cancer [cervical intraepithelial neoplasia (CIN) grade 3 and adenocarcinoma in situ (AIS)], cervical pre-cancers [cervical intraepithelial neoplasia (CIN) grade 2], vulvar pre-cancers [vulvar intraepithelial neoplasia (VIN) 2/3)] and vaginal pre-cancers [vaginal intraepithelial neoplasia (VaIN) 2/3], and for the prevention of genital warts and low-grade cervical lesions (CIN 1) caused by HPV types 6, 11, 16 and 18. GARDASIL is contraindicated in individuals who are hypersensitive to the active substances or to any of the excipients of the vaccine.

Studies assessed CIN 2/3, the most meaningful efficacy measure

The studies, FUTURE I and FUTURE II, are phase III, prospective, double-blind, placebo-controlled randomized studies conducted in 29 countries. The women who participated in the trials were 15 to 26 years old at enrollment; they received three doses of either GARDASIL or placebo at day one, month two and month six. The primary analyses of these trials evaluated the efficacy of GARDASIL compared to placebo in women who were free of infection with the relevant HPV types (6, 11, 16 and/or 18) when they started the study, remained free of infection with the relevant HPV types through month seven, received all three doses of GARDASIL within one year and had no protocol violations.

FUTURE I was designed to evaluate the impact of GARDASIL on the incidence of cervical lesions and pre-cancers (CIN 1-3), vulvar and vaginal external lesions and pre-cancers (VIN 1-3 and VaIN 1-3) and external genital warts caused by the four HPV types targeted by the vaccine (HPV 6, 11, 16 and 18). FUTURE II was designed to evaluate the impact of GARDASIL on pre-cancers and non-invasive cancers (CIN 2/3, AIS) caused by HPV 16 and 18. Prevention of advanced, or high grade cervical pre-cancerous lesions -- CIN 2/3 or AIS -- has been identified by the FDA and World Health Organization as the most meaningful indicator of cancer efficacy for a cervical cancer vaccine.

Results showed that GARDASIL provided significant protection in women not previously exposed to HPV types targeted by the vaccine

In FUTURE I, after an average follow-up of three years, GARDASIL provided 100 percent protection from HPV 6-, 11-, 16- and 18-related VIN 1-3, VaIN 1-3 and genital warts; no cases were observed in the vaccine group (n=2,261) compared to 60 cases in the placebo group (n=2,279). GARDASIL was also 100 percent effective for the prevention of HPV 6-, 11-, 16-, or 18-related CIN 1-3; there were no cases observed in the vaccine group (n=2,241) compared to 65 cases in the placebo group (n=2,258).

In FUTURE II, after an average follow-up of three years, GARDASIL was 98 percent effective in preventing high-grade cervical pre-cancers associated with HPV types 16 and 18; one case of CIN 3 was observed in the vaccine group (n=5,305) compared to 42 cases in the placebo group (n=5,260).

Studies assessed efficacy of GARDASIL in the general population of women

The studies also assessed the efficacy of GARDASIL in the general population of women, including those infected with HPV (and who may have had HPV-related disease) at the start of the trials. In FUTURE I, GARDASIL reduced the rate of cervical lesions caused by vaccine or other HPV types by 20 percent; 344 cases were observed in the vaccine group (n= 2,723); 421 cases were observed in the placebo group (n=2,732). GARDASIL reduced the rate of vaginal or vulvar lesions and genital warts caused by vaccine or other HPV types by 34 percent; 104 cases were observed in the vaccine group (n= 2,723); 157 cases were observed in the placebo group (n=2,732). In FUTURE II, vaccination with GARDASIL reduced the rate of CIN 2/3 and AIS caused by vaccine or other HPV types by 17 percent; 219 cases were observed in the vaccine group (n= 6,087); 266 cases were observed in the placebo group (n=6,080). In both studies, the majority of lesions occurred among women who were already HPV-infected at the start of vaccination. Vaccination with GARDASIL did not change the course of these pre-existing infections. Infections present at the start of vaccination caused most of the lesions in the early period of follow-up; however, over three years, the impact of the vaccine became more apparent, as lesions caused by new infections with vaccine HPV types were observed in the placebo group but not in the vaccine group.

In both studies, the adverse events observed were similar to what has been previously reported.

Additional important information about GARDASIL

The health-care provider should inform the patient, parent or guardian that vaccination does not substitute for routine cervical cancer screening. Women who receive GARDASIL should continue to undergo cervical cancer screening per standard of care.

Vaccination with GARDASIL may not result in protection in all vaccine recipients. GARDASIL is not intended to be used for treatment of active genital warts; cervical cancer; CIN, VIN, or VaIN. GARDASIL has not been shown to protect against disease due to other HPV types.

In clinical studies for GARDASIL, vaccine-related adverse experiences that were observed at a frequency of at least 1.0 percent among recipients of GARDASIL and also greater than those observed among recipients of placebo, respectively, were pain (83.9 percent vs. 75.4 percent), swelling (25.4 percent vs. 15.8 percent), erythema (24.6 percent vs. 18.4 percent), fever (10.3 percent vs. 8.6 percent), nausea (4.2 percent vs. 4.1 percent), pruritis (3.1 percent vs. 2.8 percent) and dizziness (2.8 percent vs. 2.6 percent).

Dosage and administration for GARDASIL

GARDASIL is a ready-to-use, three-dose, intramuscular vaccine. GARDASIL should be administered in three separate intramuscular injections in the upper arm or upper anterior thigh over a six-month period. The following dosage schedule is recommended: first dose at elected date, second dose two months after the first dose and the third dose six months after the first dose.

GARDASIL is widely available throughout the United States

There is broad private and public health insurance coverage for GARDASIL. Health plans covering approximately 98 percent of privately insured lives in the U.S. (currently more than 140 insurance plans) have implemented coverage for GARDASIL; however, individual benefit coverage and rates provided by health plans may vary.

GARDASIL was also added to the Vaccines for Children (VFC) Program on November 1, 2006, providing coverage for many who do not have private health insurance. All of the 55 immunization projects in the U.S. have adopted GARDASIL and most are filling provider orders.

Merck has also initiated a new patient assistance program for vaccines. Through this program, currently available in private physicians' offices and private clinics, Merck is making available, free of charge, GARDASIL and other Merck vaccines indicated for use in individuals ages 19 and older who are uninsured and who are unable to afford vaccines.

GARDASIL is approved in 70 countries

GARDASIL (sold in some countries as SILGARD®) has been approved in 70 countries, including the United States, the 27 countries of the European Union, Mexico, Australia, Taiwan, Canada, New Zealand and Brazil, and additional applications are currently under review with regulatory agencies in many more countries around the world.

Merck will donate free vaccine to the non-profit organization PATH to support demonstration studies designed to accelerate the availability of cervical cancer vaccines in the most impoverished nations. PATH is funded by a grant from the Bill & Melinda Gates Foundation. Merck is also working with India's Council of Medical Research to study GARDASIL in India. Merck will make its new vaccines, including GARDASIL, available to developing world countries at dramatically lower prices.

HPV is a common infection

In the United States, approximately 20 million people are infected with HPV, and approximately 80 percent of females will have acquired HPV by age 50. For most people, HPV goes away on its own; however in some, certain high-risk types of HPV, if unrecognized and untreated, can lead to cervical cancer. Cervical cancer is the second most common cause of cancer death in women worldwide, resulting in nearly a half-million diagnoses and 240,000 deaths each year. It is estimated that in 2007, there will be approximately 11,150 new cases of cervical cancer and 3,700 deaths in the United States. Approximately 6,000 cases of vulvar or vaginal cancer are diagnosed annually in the U.S.

Certain low-risk types of HPV cause genital warts and can lead to abnormal Pap results. Approximately one million cases of genital warts occur each year in the United States and an estimated 32 million cases occur worldwide. Additionally, there are an estimated 4.7 million abnormal Pap results that require follow-up each year in the United States. At least 3 million of these results are caused by some type of HPV.

Other Information about GARDASIL

In 1995, Merck entered into a license agreement and research collaboration with CSL Limited of Australia relating to technology used in GARDASIL. GARDASIL also is the subject of other third-party licensing agreements.

Merck recently announced that it submitted a supplemental Biologics License Application (sBLA) to the FDA that includes efficacy data showing GARDASIL offers some protection against additional cervical cancer causing HPV types responsible for greater than 10 percent of cervical cancers, data on protection against additional gynecological cancers -- vaginal and vulvar -- and data on immune memory.

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 http://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, 2006, and in its periodic reports on Form 10-Q and Form 8-K, which the Company incorporates by reference.

GARDASIL® is a registered trademark of Merck & Co., Inc., Whitehouse Station, N.J., U.S.A.