Non-Insured Health Benefits (NIHB) Program

[AIDSDrug for FirstNations]

INNOVATIVE HIV-AIDS TREATMENT ISENTRESS™ NOW AVAILABLE TO CANADIAN FIRST NATIONS

Montreal, Québec – October 7, 2008 – Canadian First Nations people living with HIV-AIDS will now have access to ISENTRESS™ (raltegravir), the first of a new class of antiretrovirals for the treatment of HIV-AIDS through Health Canada’s Non-Insured Health Benefits (NIHB) Program. The NIHB program provides coverage for health-related needs for First Nations, Inuit and Aboriginal people.

“The Canadian Aboriginal AIDS Network welcomes the release of new medications to treat HIV, " said Ken Barlow, Chief Executive Officer. "CAAN continues to encourage Aboriginal people living with HIV-AIDS to seek medical advice and get informed about medical advancements that can help manage their illness."

This inclusion in the NIHB list of medication is particularly relevant because the overall HIV infection rate among Aboriginal persons is almost three times higher than among non-Aboriginal Canadians, making need for new treatment options that target the HIV virus in new ways critical.1

About ISENTRESS™
ISENTRESS™ (raltegravir) was approved by Health Canada in November 2007 for use in combination with other antiretroviral agents for the treatment of HIV-1 infection in treatment-experienced adult patients who have evidence of viral replication and HIV-1 strains resistant to multiple antiretroviral agents. Raltegravir attacks the HIV virus in a way that’s different to other available antiretroviral treatments. It is the only drug approved that blocks the action of integrase, an enzyme that is critical to the HIV replication process. By targeting the integrase enzyme, raltegravir limits the ability of the virus to replicate and infect new cells. Used in combination with other antiretroviral agents, raltegravir has been shown to be effective at both reducing viral load to undetectable levels and raising CD4 cell count in people living with HIV-AIDS who were previously treated with other antiretroviral agents. Raltegravir is administered as a single 400 mg tablet taken twice daily with or without food with other HIV medications. 2

About HIV-AIDS in Canada
• As of June 2006, 61,423 people in Canada have tested positive for HIV. Of these people, 83.5% are male and 16.5% are female.3
• Of the estimated 58,000 people living with HIV/AIDS at the end of 2005 in Canada, approximately 27% were unaware of their HIV status. 4
• The number of new HIV infections in 2005 has not decreased and may have increased slightly compared to 2002 .3
• In Canada, 11 new people are infected with HIV every day.5

Merck Frosst’s Commitment to HIV Research
Merck Frosst is committed to developing innovative therapies that offer advances in the treatment of infectious diseases – including HIV. The Company's efforts to develop investigational treatments for HIV-AIDS have been under way for more than 20 years and continue today. We began our HIV integrase inhibitor research in 1993 and were the first to demonstrate inhibition of HIV integrase in vitro and in vivo.

Merck's commitment to providing access to treatment
Merck is committed to ensuring access to our antiretroviral medicines (ARVs) through a differential pricing policy that provides our ARVs at dramatically lower prices-at which Merck does not profit-to people living in the world's least developed countries and those hardest hit by the pandemic, as defined by various United Nations indices. Also, Merck is committed to seeking additional ways to reduce the cost of its ARVs for people living in the world's poorest countries and those hardest hit by the pandemic, including through partnering with external manufacturers and suppliers to achieve incremental efficiencies and cost savings.

About Merck Frosst Canada Ltd.
At Merck Frosst, patients come first. Merck Frosst Canada Ltd. is a research-driven pharmaceutical company discovering, developing and marketing a broad range of innovative medicines and vaccines to improve human health. Merck Frosst is one of the top 25 R&D investors in Canada, with an investment of close to $110 million in 2007. More information about Merck Frosst and ISENTRESS™ is available at www.merckfrosst.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 cautionary statements in Item 1A of Merck's Form 10-K for the year ended Dec. 31, 2007, and in its periodic reports on Form 10-Q and Form 8-K, which the Company incorporates by reference.
™ Trademark of Merck & Co., Inc., used under license.
For further information, please contact:
Martine Drolet
Merck Frosst Canada Ltd.
(514) 428-3037
(514) 833-6780
References:
1. Public Health Agency of Canada. HIV/AIDS Epi Updates. August 2006
2. ISENTRESSTM product monograph
3. Public Health Agency of Canada. HIV and AIDS in Canada; Surveillance Report to June 30, 2006. November 2006
4. Public Health Agency of Canada. HIV/AIDS Epi Updates. August 2006
5. http://www.farha.qc.ca/en/html/sidaqc.html Last accessed September 26, 2008.