Posted: 15 May 2008
New study identifies most effective initial treatment for HIV
The largest study of its kind to evaluate commonly-used HIV drugs has been able to confirm that one of the most frequently prescribed triple-drug combinations for initial HIV-1 infection is, the most effective at suppressing HIV. The findings were published in the 15 May 2008 issue of New England Journal of Medicine. The study team also found that a two-drug regimen performed comparably for patients susceptible to severe side effects.
The study looked at one of the first classes of HIV drugs approved by the U.S. Food and Drug Administration called nucleoside reverse transcriptase inhibitors (NRTIs) and a two-drug regimen that did not include NRTIs. Although effective and commonly prescribed, NRTIs can produce severe side effects in some patients.
Far right: Image of the Human Immunodeficiency Virus (HIV)
Professor Bill Powderly, Dean of Medicine at UCD and one of the co-authors of the research, explained the implications of the findings. “Even when various treatments become available on the market, it is extremely important to study their relative effectiveness and their side effects. In the case of this study we were able to establish which 3-drug treatment was most effective in the initial stages of HIV infection treatment and we also established that one 2-drug treatment is effective for patients who experience side effects from NRTIs.”
There are currently at least 2,000 HIV patients being treated in Irish hospitals. Approximately 400 new patients are diagnosed each year and at least half require immediate therapy. “Advances in medical research mean fewer side effects, fewer pills and more effective long term treatment. Our patients are living longer and more normal lives.” Professor Powderly added.
The study, which included 753 participants at 55 centres in the US and South Africa, found that the popular three-drug combination of efavirenz plus NRTI therapy was more effective at achieving and maintaining reduction of the virus than another commonly prescribed drug combination of lopinavir-ritonavir plus NRTI. Interestingly, a two-drug combination of lopinavir-ritonavir plus efavirenz had a similar level of effectiveness as each of the triple-drug regimens that contained NRTIs. HIV levels in 24 percent of the participants in the efavirenz group returned to detectable levels during the almost two-year study compared to 33 percent of participants in the lopinavir-ritonavir group and 27 percent of those in the NRTI-sparing group. All three treatment regimens produced substantial improvements in immune responses.
“Although all three regimens were well-tolerated and effective, our results showed that efavirenz with NRTIs should still be considered the gold standard regimen for initial HIV treatment,” said Sharon Riddler, M.D., M.P.H., lead author of the study and associate professor of medicine in the division of infectious diseases at the University of Pittsburgh School of Medicine. “The results from the NRTI-sparing regimen have given us valuable reassurance that we can utilise a two-drug therapy regimen based on lopinavir-ritonavir plus efavirenz for patients who are unable to take NRTI due to side effects.”
“This study not only establishes the best initial therapy for HIV infection, it opens the way toward simpler regimens that contain fewer drugs,” said Professor Powderly.
Professor Powderly is principal investigator for the Dublin HIV Cohort, a project funded by the Health Research Board to study the natural history and complications of HIV in a diverse population of patients infected with the virus. This study currently includes over 1,000 patients from the Mater Hospital, St James Hospital and Beaumont Hospital. The Dublin cohort is particularly pertinent because HIV infection in Dublin is essentially three separate epidemics - sexually transmitted disease (mainly homosexual men), infection in drug-using patients and infection in the immigrant population.
A recent announcement by Molecular Medicine Ireland gave details of the appointment of Dr Eoin Feeney as Clinical Fellow working alongside Dr Paddy Mallon, UCD Lecturer in Medicine and Consultant in Infectious Diseases at the Mater Misericordiae University Hospital. Dr Feeney’s work will concentrate on the mechanism of long term side effects of NRTIs and in particular how they can contribute to diseases such as diabetes and heart disease.
The published study was conducted as part of the AIDS Clinical Trials Group with funding from the National Institute of Allergy and Infectious Diseases in the U.S.
Prof. Powderly has been actively involved in HIV-related clinical research for the last twenty years and while in the USA held many leadership roles in the US Adult AIDS Clinical Trials Group, including Vice-Chair of the Group and chair of its Scientific Steering Committee. He was a member of numerous Advisory groups for the National Institutes of Health and the Centers for Disease Control and Prevention in the USA. He was also the first Chairman of the HIV Medicine Association in the USA.
The co-authors of the study were:
Dr Sharon Riddler M.D., M.P.H., lead author of the study and associate professor of medicine in the division of infectious diseases at the University of Pittsburgh School of Medicine and John Mellors, M.D., senior co-author and professor, University of Pittsburgh School of Medicine and University of Pittsburgh Graduate School of Public Health.
Richard Haubrich, M.D., University of California, San Diego School of Medicine; Gregory DiRienzo, Ph.D., and Lynne Peeples, M.S., Harvard School of Public Health; William Powderly, M.D., University College, Dublin, Ireland; Karin Klingman, M.D., National Institute of Allergy and Infectious Diseases, Division of AIDS.; Kevin Garren, Ph.D., Abbott Laboratories, Abbott Park, Ill.; Tania George, Pharm.D., Bristol-Myers Squibb, Plainsboro, N.J.; James Rooney, M.D., Gilead Sciences, Foster City, Calif.; Barbara Brizz, M.S.H.Ed., B.S.N., Social & Scientific Systems, Inc., Silver Spring, Md.; Umesh Lalloo, M.D., University of KwaZulu Natal, Durban, South Africa; Robert Murphy, M.D., Northwestern University; Susan Swindells, M.B., B.S., University of Nebraska Medical Center; and Diane Havlir, M.D., University of California, San Francisco.