Etravirine reduces HIV viral loads when taken with Prezista

The experimental antiretroviral drug etravirine, made by Johnson & Johnson subsidiary Tibotec Pharmaceuticals, greatly reduces HIV viral loads in people with a history of drug resistance when taken in combination with Tibotec's antiretroviral Prezista, according to two studies published Saturday in the journal The Lancet, the Los Angeles Times reports (Chong, Los Angeles Times, 7/6).

The Lancet has published an HIV/AIDS themed issue ahead of the 4th International AIDS Society Conference On HIV Pathogenesis, Treatment and Prevention, which is scheduled to take place July 22 to July 25 in Sydney, Australia (AFP/Yahoo! News, 7/6).

The two Phase III studies, which were funded by Tibotec, followed 1,203 HIV-positive people in 19 countries who had compromised immune systems and a history of resistance to two classes of antiretrovirals known as non-nucleoside reverse transcriptase inhibitors and protease inhibitors, the Times reports. About half of the participants received the experimental NNRTI etravirine and the protease inhibitor Prezista and the other half received Prezista and a placebo. Participants in both groups also received other antiretrovirals based on their physicians' recommendations. One of the studies found that at 24 weeks, 62% of the participants who received etravirine saw a decrease in their HIV viral loads to undetectable levels, compared with 44% in the placebo group. The second study found successful viral suppression in 56% of participants who received etravirine, compared with 39% who received a placebo (Los Angeles Times, 7/6). According to AFP/Yahoo! News, side effects in both groups were mild or moderate (AFP/Yahoo! News, 7/5).

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David Hardy, director of infectious diseases at Cedars-Sinai Medical Center who was not involved with the studies, said the results suggest that etravirine is best used in combination with other antiretrovirals that have a strong ability to control HIV. Etravirine "will not perform by itself," Hardy added (Los Angeles Times, 7/6). William Towner, medical director of Kaiser Permanente's HIV/AIDS Research Trials Program in Southern California and a study author, said the studies are the "most significant worldwide HIV/AIDS clinical trials in recent years." Towner added that the studies "showed that when the two drugs are used in combination, there is a good chance HIV can be very effectively controlled in patients who have advanced, multi-drug resistant HIV" (Reuters, 7/5).

An abstract of the first study is available online. An abstract of the second study also is available online.

Related Studies

The Lancet on Saturday also published a number of other articles ahead of the IAS conference. Summaries appear below.

• "The Sydney Declaration: A Call To Scale Up Research": This commentary presents a sign-on declaration calling on "national governments and bilateral, multilateral, and private donors to allocate 10% of all resources for HIV programming to research." While funding "remains insufficient to meet the increasing need for services," the commentary also argues that the global community should "not lose sight of the future while responding to the immediate crisis." The authors conclude that in the absence of research funding "we will fail to maintain a sustained and effective response to the AIDS pandemic" (Cooper et al., The Lancet, 7/7). An accompanying editorial says that the declaration will be "perhaps one of the most important things to come out of the meeting" (The Lancet, 7/7).
• "Incidence of Cancers in People With HIV/AIDS Compared With Immunosuppressed Transplant Recipients: A Meta-Analysis": For the study, Andrew Grulich of the National Centre in HIV Epidemiology and Clinical Research at the University of New South Wales and colleagues analyzed the results of 12 earlier studies conducted in Australia, Canada, Europe and the U.S. among more than 444,000 HIV-positive people and 32,000 organ recipients who received long-term immunosuppressive therapy. They found that HIV-positive people and transplant recipients are at a higher risk of developing several cancers than the general population, AFP/Yahoo! News reports. The study found that both groups have an increased risk of developing 20 of the 28 cancers studied, including cancer of the liver, stomach, cervix, eye, lip, mouth and penis. The study also found that HIV-positive people are 11 times more likely than the general population to develop Hodgkin's lymphoma. Most of the 20 cancers were linked to infections, Grulich said, adding that both groups were no more likely than the general population to develop cancers not linked to viruses or bacteria, such as prostate or breast cancer. "What we found is that the extent of cancer occurrences in these two populations was very similar," Grulich said. He added that the findings "suggest that immune deficiency is associated with risk of cancer and this suggests we need to maintain people's immune systems at a higher level -- and that might mean putting HIV patients on antiretroviral drugs earlier than is currently the case." Grulich said that the findings could overturn the view that some of the cancers are linked to lifestyle factors, such as smoking or sexual practices, rather than infection (AFP/Yahoo! News, 7/6).
• "Efficacy and Safety of Darunavir-Ritonavir Compared With That of Lopinavir-Ritonavir at 48 Weeks in Treatment-Experienced, HIV-Infected Patients in TITAN: A Randomized Controlled Phase III Trial": For the study, researchers examined whether the protease inhibitor Prezista, generically known as darunavir, boosted by ritonavir is as effective as Abbott Laboratories' antiretroviral Kaletra, generically known as lopinavir-ritonavir, the Newark Star-Ledger reports. The study enrolled 595 participants and found that 70% who took Prezista reduced their HIV viral loads to less than 50 virus copies per milliliter of blood, which is considered undetectable, compared with 61% of participants who took Kaletra. In an accompanying editorial, Bernard Hirschel and Thomas Perneger, both of the University of Geneva, said that the study likely will not lead to Kaletra being replaced by Prezista because Prezista is more expensive (May, Newark Star-Ledger, 7/6).

The themed issue of The Lancet is available online.

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