Raltegravir drug combo works against highly resistant strain of HIV

Jul 24 2008

A study involving an international team of scientists has discovered that a new drug when combined with other anti-HIV medications, is particularly effective against a highly resistant strain of the HIV virus.

The new drug, raltegravir, offers hope to millions afflicted with this particular strain of the virus.

The study which was led by Dr. Roy T. Steigbigel, a professor of Medicine, Pathology, Microbiology and Pharmacological Sciences at Stony Brook University Medical Center, in New York, found that patients who had not responded to traditional treatments had good results with the new combination therapy.

Dr. Steigbigel says HIV disease is very complex and is especially difficult to manage in patients whose virus has become resistant to therapy.

The study involved 699 patients at 15 sites over a 48 week period of therapy and demonstrated that raltegravir when combined with other anti-HIV drugs, lowered the amount of virus in the blood to undetectable levels in 62 percent of people taking it.

The research was co-authored by Professor David Cooper from the University of New South Wales' (UNSW) National Centre in HIV Epidemiology and Clinical Research (NCHECR) and he says raltegravir is the first drug in a new class of antiretroviral drugs called integrase inhibitors.

Professor Cooper says it has a different mechanism of action, is very potent, but appears to be safe and has helped patients who have a virus that is resistant to older drugs.

The results come from two major ongoing clinical trials in patients in Europe, Asia, Australia, and North and South America, comparing the drug in combination with other anti-HIV medicines to a placebo plus other anti-HIV medicines.

According to Professor Cooper, the results after 48 weeks of treatment are consistent with those seen at 24 weeks and the therapeutic regimen was well tolerated by patients.

The most commonly reported side effects were diarrhea, nausea, injection site pain or reaction and headache.

Dr. Steigbigel says in total, 462 patients received the new drug and 237 received the placebo and the combination therapy helped the immune system to rebound in most patients.

Professor Cooper says the new drug will initially be used in developed countries, but will hopefully be made available at cheaper prices for patients in developing countries.

Raltegravir is already available in Australia and is listed on the Pharmaceutical Benefits Scheme.

Involved in the study, with Stony Brook University Medical Center and the University of New South Wales were the University of North Carolina, Chapel Hill; Universidade Federal do Rio de Janeiro, Brazil; The Rockefeller University, New York; University of Toronto, Canada; Emory University School of Medicine; University of Barcelona, Spain; University of Bonn in Germany; Universite Pierre et Marie Curie in Paris, France; Hospital Bichat-Claude Benard, Paris, France; San Raffaele Scientific Institute, Milan, Italy; Hospital Germans Trias I Pujoy in Barcelona and Catalonia, Spain, and Merck Research Laboratories in Pennsylvania.

The study is published in the New England Journal of Medicine.