FDA Advisory Committee Votes Unanimously That Clinical Data Support the Efficacy and Safety of GARDASIL®, Merck's Investigational Cervical Cancer Vaccine; If Approved, GARDASIL Will Be the First Cervical Cancer Vaccine in the U.S

Business Wire, May 18, 2006

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 voted unanimously that the data from Phase II and Phase III clinical trials support the efficacy and safety of GARDASIL(R) (quadrivalent human papillomavirus (Types 6, 11, 16, 18) recombinant vaccine) for the prevention of cervical cancer and for the prevention of cervical, vulvar and vaginal pre-cancers caused by human papillomavirus (HPV) types 16 and 18 in females. The Committee also agreed that data support the efficacy and safety of GARDASIL for the prevention of other cervical, vulvar and vaginal lesions caused by HPV types 6, 11, 16 and 18 including genital warts.

The Committee's guidance will be considered by the FDA in its review of the Biologics License Application (BLA) that Merck submitted for GARDASIL in December 2005. The FDA has informed Merck that the target date for completion of review is June 8, 2006. The Committee also recommended that Merck continue to develop and conduct post-licensure studies to assess the safety and efficacy of GARDASIL if it is approved for use. The FDA is not bound by the committee's guidance, but takes its advice into consideration when reviewing investigational vaccines seeking approval.

"Merck is thrilled that the Advisory Committee has agreed that the extensive data from our decade-long, 27,000-patient clinical trial program support the use of GARDASIL to reduce the burden of cervical cancer and other diseases caused by HPV," said Peter S. Kim, Ph.D., president, Merck Research Laboratories. "If approved, GARDASIL will be the first and only vaccine to prevent cervical cancer and other serious HPV-related diseases. We look forward to bringing this vaccine to people to continue our legacy of bringing forward novel medicines and vaccines that address unmet medical needs for people around the world."

Diseases caused by HPV represent a major burden in the United States. Approximately 10,000 women are diagnosed with cervical cancer each year, and an average of 10 women die each day from this cancer. HPV also causes approximately 40 to 50 percent of the more than 3,500 cases of vulvar and vaginal cancer that are diagnosed each year in the U.S.; about three women die each day from these two cancers. HPV-related diseases cost about $5 billion per year in the United States.

GARDASIL is Merck's investigational cervical cancer vaccine designed to protect against four types of human papillomavirus (HPV types 6, 11, 16 and 18). HPV types 16 and 18 account for an estimated 70 percent of cervical cancer cases and can lead to vulvar and vaginal cancers. HPV types 6 and 11 account for an estimated 90 percent of genital wart cases and can cause abnormal Pap tests and low-grade cervical abnormalities.

In studies, GARDASIL prevented 100 percent of cervical cancers and pre-cancers caused by HPV types 16 and 18

Results from Merck's clinical trials, presented to the Advisory Committee, evaluated the efficacy, safety and immunogenicity of GARDASIL in more than 27,000 females and males and from 33 countries around the world. In the key efficacy studies in 20,887 women aged 16 to 26, GARDASIL prevented 100 percent of cervical, vaginal and vulvar pre-cancers caused by HPV types 16 and 18, prevented 95.2 percent of cervical lesions caused by HPV types 6, 11, 16 and 18, and prevented 99.1 percent of external genital lesions, including genital warts, caused by HPV types 6, 11, 16 and 18. Specifically, in women aged 16 to 26 who were free from infection with HPV types 16 and 18 at the start of the study and who received all three doses of GARDASIL:

--Prevention of cervical pre-cancers and non-invasive cancers caused by HPV 16 and HPV 18: GARDASIL prevented 100 percent of HPV 16- or 18-related CIN 2/3 (cervical intraepithelial neoplasia) or adenocarcinoma in situ (AIS). There were no cases in the 8,487 women who received GARDASIL compared to 53 cases in the 8,460 women who received placebo. National and international health agencies including the FDA and the World Health Organization have maintained that demonstrated efficacy against pre-cancers (CIN 2/3) is the most clinically relevant measure of a cervical cancer vaccine's effectiveness.

--Prevention of vaginal and vulvar pre-cancers caused by HPV 16 and HPV 18: GARDASIL prevented 100 percent of HPV 16- or 18-related VIN 2/3 (vulvar pre-cancers) or VaIN 2/3 (vaginal pre-cancers). There were no cases in the 8,641 women who received GARDASIL compared to 24 cases in 8,667 women who received placebo.

In women aged 16 to 26 who were free from infection with HPV types 6, 11, 16 and 18 at the start of the study and who received all three doses of the vaccine:

--Prevention of cervical lesions caused by HPV 6, HPV 11, HPV 16, and HPV 18: GARDASIL prevented 95.2 percent of HPV 6-, 11-, 16- or 18-related cervical lesions (CIN 1), CIN 2/3 or AIS. There were 4 cases in the 7,858 women who received GARDASIL compared to 83 cases in the 7,861 women who received placebo.