Merck is committed to pursuing rapid registration of our antiretrovirals (ARVs), including in those countries most affected by HIV/AIDS.

Currently, Merck ARVs are registered or available through import in many countries. Since the first approval in 2007, ISENTRESS^® (raltegravir) has received regulatory approval in more than 90 countries for use in treatment-experienced adult patients infected with HIV-1 and in 47 countries for use in treatment-naïve adult patients infected with HIV-1. Merck is in the process of filing ISENTRESS in additional countries around the world. To increase the transparency of the Company's product registration status, we are disclosing registration for our four ARVs:

• ATRIPLA
• CRIXIVAN
• ISENTRESS
• STOCRIN

World Health Organization (WHO) Prequalification

STOCRIN^® (efavirenz), CRIXIVAN^® (indinavir sulfate) and ATRIPLA^® (efavirenz) have received World Health Organization (WHO) prequalification. Merck is committed to working with WHO for the prequalification of ISENTRESS. WHO prequalification verifies that medicines meet the requirements of quality, safety and efficacy of UN agencies, including UNICEF and the Pan American Health Organization, and is an important step toward providing global access.