Merck NEWS UPDATE

• The National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH, and the NIAID-funded HIV Vaccine Trials Network announced that vaccination in the STEP clinical trial of Merck's HIV vaccine candidate would be discontinued . The decision was based on recommendations made by an independent Data and Safety Monitoring Board for the STEP trial, which concluded that the vaccine could neither prevent HIV infection nor reduce the amount of virus in those who became infected with HIV.

• Merck has been advised that the new drug application for over-the-counter MEVACOR (lovastatin) will be reviewed by the FDA Joint Meeting of the Nonprescription Drugs Advisory Committee and the Endocrinologic and Metabolic Drugs Advisory Committee on December 13, 2007. Merck is seeking approval of OTC MEVACOR (lovastatin) 20 mg taken once daily to help lower cholesterol, which may prevent a first heart attack.

• In Phase IIb study results anacetrapib (formerly known as MK-0859), its investigational selective cholesteryl ester transfer protein inhibitor, significantly reduced LDL-cholesterol and Apolipoprotein B and increased HDL-cholesterol and Apolipoprotein A-1 both as monotherapy and in combination with atorvastatin 20 mg compared to placebo in patients with dyslipidemia.

• CANCIDAS® (caspofungin acetate), given once daily, was evaluated as a treatment for patients three months to 17 years of age with documented or suspected fungal infections. The use of CANCIDAS in pediatric patients is investigational. Interim results from the first Phase II clinical trial to study this therapy in pediatric patients with invasive candidiasis, esophageal candidiasis or invasive aspergillosis (as salvage therapy only) will be presented.