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Isentress Shown to Be More Effective in Ongoing Head-to-Head HIV Study

Favourable long-term tolerability and metabolic profile

MONTREAL, Oct. 20, 2011 /CNW Telbec/ - For the first time, after 192 weeks of the ongoing STARTMRK head-to-head study comparing Merck's integrase inhibitor ISENTRESS® (raltegravir) used in combination therapy to an efavirenz-based combination therapy, a product has demonstrated superior antiretroviral efficacy in previously untreated HIV-infected patients. These data are being presented at the 49th Annual Meeting of the Infectious Diseases Society of America (IDSA) in Boston, Massachusetts from October 20-23, 2011.

"The new STARTMRK results show that raltegravir was more effective, better tolerated and had less impact on lipids, including cholesterol, in treatment-naïve patients," said Dr. Colin Kovacs, a Canadian STARTMRK investigator and a primary care physician with 17 years of HIV/AIDS clinical care experience. "These results demonstrate just how much HIV treatments continue to evolve."

STARTMRK is an ongoing multicenter, double-blind, active-controlled, Phase III non-inferiority study, with 563 patients randomized to receive either raltegravir or efavirenz, both in combination with the backbone therapy tenofovir/emtricitabine. Primary analysis was at week 48 and secondary analysis at week 96. In this new pre-specified exploratory analysis after 192 weeks, 76.2% (n=214/281) of raltegravir patients versus 67% (n=189/282) of efavirenz patients (95% confidence interval (CI) 1.6, 16.4) had HIV RNA concentration ("viral load") of less than 50 copies per mL - the goal of therapy. The regimen containing raltegravir also showed a greater immunological effect with a greater increase in CD4 cell count from baseline (360.7 cells/mm3 for raltegravir vs. 300.9 cells/mm3 for efavirenz; 95 percent CI 24.1, 95.4). CD4 cells are a subset of white blood cells that help fight HIV infection.

Fewer adverse events and drug discontinuations
Drug-related clinical adverse events occurred less often with raltegravir than efavirenz (50% vs. 80%; p<0.001). Raltegravir was generally well tolerated with fewer discontinuations due to clinical adverse events (5% for raltegravir vs. 8% for efavirenz). At week 192, raltegravir also had less impact on fasting lipids.

30th anniversary of HIV/AIDS epidemic
"When the HIV/AIDS epidemic struck 30 years ago, HIV was a death sentence. Then triple therapy emerged, but the early drugs were associated with very challenging side effects," stated Dr. Réjean Thomas, who founded in 1987 the Montreal-based Clinique médicale l'Actuel, a pioneer in the treatment of HIV/AIDS. "Today the treatment paradigm has evolved to lifelong therapy and we are more concerned with managing the potential development of other chronic diseases. In this context, it is important to note that raltegravir has little effect on the kidney, liver, blood sugar and cholesterol."

An estimated 65,000 Canadians were living with HIV infection at the end of 2008 and non-AIDS related events are becoming a prominent cause of sickness and death in this population.2

In 2009, Ontario accounted for 41.9% of all positive HIV tests reported to the Public Health Agency of Canada (PHAC), followed by Quebec (21.4%), British Columbia (14.0%), Alberta (9.1%) and Saskatchewan (8.2%).3

Men who have sex with men (MSM) accounted for over 80% of all HIV cases in 1985, but just 41.8% in 2009.4 Women accounted for approximately 25% of HIV diagnoses in Ontario between 2002 and 2008, compared to 3% prior to 2001.5 Also, Aboriginals continue to be overrepresented in the HIV epidemic in Canada and are making up a growing percentage of prevalent HIV infections, increasing by 24% from 2005 to 2008.

ISENTRESS® (raltegravir) is the only integrase inhibitor approved in Canada. By blocking the action of the integrase enzyme, raltegravir limits the ability of the HIV virus to replicate and infect new cells.

Raltegravir is indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus (HIV−1) infection in adult patients. This indication is based on the evidence of efficacy of ISENTRESS® from the analysis of 96-week data from three ongoing, randomized, double-blind, controlled trials. Two of these studies, BENCHMRK 1 and BENCHMRK 2, were conducted in antiretroviral treatment-experienced HIV-1 infected adult patients and one, STARTMRK, was conducted in treatment-naïve adults.7

Raltegravir has been available in Canada for use in treatment-experienced patients since November 2007 and for adults starting HIV treatment for the first time since October 2009.

About Merck
Today's Merck is a global healthcare leader working to help the world be well. Merck is known as MSD outside the United States and Canada. Through our medicines, vaccines, biologic therapies, and consumer and animal products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to healthcare through far-reaching policies, programs and partnerships. For more information about our operations in Canada, visit

Forward Looking Statement
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ISENTRESS® is a Registered Trademark of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc. Used under license.


1 Public Health Agency of Canada. HIV/AIDS EPI Updates June 2010. Chapter 1: National HIV Prevalence and Incidence Estimates in Canada for 2008. Accessed at:
2 Therapeutic Guidelines. Antiretroviral treatment (ARV) of adult HIV infection. British Columbia Centre for Excellence in HIV/AIDS. January 2011. Page 33.
3 Public Health Agency of Canada. Surveillance Report to December 2009. Accessed at:
4 Public Health Agency of Canada. Surveillance Report to December 2009. Accessed at:
5 Ontario Women's Health Equity Report. Accessed at:
6 Public Health Agency of Canada. HIV/AIDS EPI Updates June 2010. Chapter 8: HIV/AIDS Among Aboriginal People in Canada. Accessed at:
7 ISENTRESS® Product Monograph. September 8, 2010. Accessed at:


For further information:

Sheila Murphy

Roch Landriault/Stephanie Lyttle
NATIONAL Public Relations


Posted: October 2011