HIV drug maraviroc effective for drug-resistant patientsOctober 02, 2008As many as one quarter of HIV patients have drug resistance, limiting their treatment options and raising their risk for AIDS and death. Now, maraviroc, the first of a new class of HIV drugs called CCR5 receptor antagonists, has been shown to be effective over 48 weeks for drug-resistant patients with R5 HIV-1, a variation of the virus found in more than half of HIV-infected patients. Results of the two Phase 3 multicenter MOTIVATE (Maraviroc Plus Optimized Therapy in Viremic Antiretroviral Treatment Experienced Patients) studies led by NewYork-Presbyterian Hospital/Weill Cornell Medical Center's Dr. Roy Gulick and published in the October 2 issue of the New England Journal of Medicine (NEJM) find that the drug, taken with an optimized standard HIV drug regimen, resulted in significantly greater suppression of the virus at 48 weeks, with concurrent increases in immune system T-cell counts, when compared with placebo. Rates of side effects were not different between the maraviroc and placebo groups. Preliminary results of these studies led to FDA approval of maraviroc in August 2007. Because it is from a new class of HIV medications known as HIV entry inhibitors, people living with HIV generally will not have resistance to maraviroc because they have not been exposed to any drugs from the class previously. Unlike earlier HIV drugs that target the virus, maraviroc acts on the human T-cell, binding to it in such a way that prevents HIV from binding and subsequently infecting the T-cell. "It is now possible to expect that a majority of treatment-experienced patients who experience failure on their current HIV drugs will regain control of their HIV infection with maraviroc combined with other newer antiretroviral drugs. This is an important step forward," says study principal investigator Dr. Roy Gulick, who is professor of medicine and director of the Cornell HIV Clinical Trials Unit of the Division of International Medicine and Infectious Diseases at Weill Cornell Medical College, and a practicing physician at NewYork-Presbyterian Hospital in New York City. "Suppressing virus levels and increasing immune system T-cells with HIV treatment regimens helps HIV-infected people live longer, healthier lives." The double-blind study followed 1,049 of patients with advanced HIV and resistance to three antiretroviral drug classes. Patients were randomized to receive maraviroc once-daily, twice-daily or placebo. Safety and efficacy were assessed at 48 weeks. The MOTIVATE studies comprised two identical arms: MOTIVATE1 was conducted in Canada and the U.S., while MOTIVATE2 was conducted in Australia, Europe and the U.S. More patients receiving maraviroc once- or twice-daily versus placebo achieved HIV-1 RNA <50 copies/mL (43-46% vs. 17%). CD4 counts increased more with maraviroc once- or twice-daily versus placebo (+116-124 vs. +61 cells/µL). Frequencies of side effects and toxicities were similar across groups. A subgroup analyses of the MOTIVATE trials is also published in the October 2 edition of NEJM. "Findings from the subgroup analyses show that maraviroc plus standard antiretroviral regimen provides consistent clinical benefit over placebo plus optimized background therapy for all subgroups analyzed," said Dr. Gerd Fätkenheuer, lead-author of the subgroup analyses and professor of medicine, Universitätsklinik Köln, Köln, Germany. "Results highlight that maraviroc provides a valuable additional treatment option for a wide spectrum of treatment-experienced patients with R5 HIV-virus infection." Currently there are 25 FDA-approved HIV medications in six classes, including HIV entry inhibitors like maraviroc, used in various combinations to treat HIV and AIDS. In cases of drug resistance, medicines lose their ability to fight HIV. Some drugs become less effective while others can become completely ineffective. As viruses reproduce, they make copy after copy of themselves, growing in number with each replication. Sometimes, small errors in one virus will be passed on to the next viral copy. Over time, viruses that contain these small errors become larger in number. These small changes in the virus's genetic make-up are called mutations. It's these mutations that cause resistance to HIV medications. Often, resistance to one medication means resistance to an entire class of medications. New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College |
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| Related Antiretroviral Current Events and Antiretroviral News Articles Many pregnant women avoid HIV screening in Africa 'Prevention is the best cure' is a common expression, but what happens if preventative measures are not used? A large proportion of pregnant Ugandan women are going out of their way not to be HIV tested, increasing the risk of mother-to-child transmission. Taking medicine for HIV proves hard to swallow for many people Highly active antiretroviral therapy has increased the longevity and quality of life for people living with human immunodeficiency virus. But it requires strict adherence in taking the medicine, something that is extremely difficult for many individuals to do. Feelings of stigmatization may discourage HIV patients from proper care The feeling of stigmatization that people living with HIV often experience doesn't only exact a psychological toll -new UCLA research suggests it can also lead to quantifiably negative health outcomes. Maternal HIV-1 treatment protects against transmission to newborns Mothers receiving highly active antiretroviral therapy (HAART) to treat HIV-1 infection are less likely than untreated mothers to transmit the virus to their newborns through breastfeeding. Research shows treating HIV-AIDS with interleukin-2 is ineffective An international research team has demonstrated that treating HIV-AIDS with interleukin-2 (IL-2) is ineffective. As a result, the researchers recommend that clinical trials on this compound be stopped. Nurses safely and effectively prescribe antiretroviral drugs in pilot program Given sufficient training and support, nurses can safely and effectively prescribe antiretroviral therapy (ART) to patients with HIV, according to a Rwandan study published in this week's PLoS Medicine. Study highlights HIV/AIDS challenge in American prison system HIV/Aids is up to five times more prevalent in American prisons than in the general population. Adherence to treatment programs can be strictly monitored in prison. Study finds nontuberculous mycobacteria lung disease on the rise in the United States Nontuberculous mycobacteria (NTM) are environmental organisms found in both water and soil that can cause severe pulmonary (lung) disease in humans. Pulmonary NTM is on the rise in the United States, according to a large study of people hospitalized with the condition. HIV vaccine regimen demonstrates modest preventive effect in Thailand clinical study In an encouraging development, an investigational vaccine regimen has been shown to be well-tolerated and to have a modest effect in preventing HIV infection in a clinical trial involving more than 16,000 adult participants in Thailand. Updated Guidelines Highlight Primary Care Needs of Those Living With HIV With HIV patients living longer thanks to advances in treatment, the primary care needs of those living with HIV have never been more important. More Antiretroviral Current Events and Antiretroviral News Articles |
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