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Antiretroviral therapy to prevent the sexual transmission of HIV-1: initial results from HPTN 052
S. Godbole1, N. Kumarasamy2, Y. Chen3, S. Chariyalertsak4, J. Hakim5, B. Santos6, B. Grinsztejn7, J. Pilotto8, M. Hosseinipour9, J. Kumwenda10, E. Filho11, K. Mayer12, M. Cohen13, HPTN 052 Protocol Team
1National AIDS Research Institute, Pune, India, 2YRG CARE, Chennai, India, 3Fred Hutchinson Cancer Research Center, Seattle, United States, 4Research Institute for Health Sciences, Chiang Mai, Thailand, 5University of Zimbabwe, Harare, Zimbabwe, 6Hospital Nossa Senhora da Conceição, Porto Alegre, Brazil, 7Instituto de Pesquisa Clínica Evandro Chagas, Rio de Janeiro, Brazil, 8Hospital Geral De Nova Iguaçu, Rio de Janeiro, Brazil, 9UNC Project, Lilongwe, Malawi, 10College of Medicine – Johns Hopkins University Research Project, Blantyre, Malawi, 11Hospital dos Servidores do Estado, Rio de Janeiro, Brazil, 12Fenway Community Health Center, Boston, United States, 13The University of North Carolina at Chapel Hill, Chapel Hill, United States
Background: Observational data show that antiretroviral therapy (ART) treatment greatly reduces the sexual transmission of HIV-1, suggesting that ART will play an important role in prevention. HPTN 052 is a study designed to determine whether ART offered at higher CD4+ cell counts can prevent the sexual transmission of HIV-1, and increase the time to the occurrence of opportunistic infections and progression to AIDS.
Methods: HPTN 052, an ongoing, prospective, two-arm, randomized, controlled, multicenter study will enroll and follow-up 1,750 HIV-1 infected individuals (index case) and their HIV-negative sexual partners (partner) for at least 5 years. These couples are randomized for ART initiation at enrollment or when the CD4+ cell count falls within or below the range of 200-250 cells/mm3. The primary study endpoint is seroconversion of the partner.
Results: 228 couples (7 male homosexual, 221 heterosexual with 96 (43%) female index cases) were recruited as of January 2008 worldwide. Of these, 222 (97.4%) index cases and 214 (93.8%) couples are in active follow-up or have reached study endpoint, with partners accruing 170 person-years of follow-up. The current 12-month retention is 96% for index cases and 90% for couples. A median 67% (IQR 65% - 67%) index cases and a median 69% (IQR 63% - 71%) of partners reported sex in the week preceding the quarterly follow-up visits, of whom a median 95% (IQR 94% - 96%) and 96% (IQR 94% - 96%), respectively, reported 100% condom use with sex.
Conclusions: It is widely believed (but unproven) that ART will help prevent the sexual transmission of HIV-1. HPTN 052 is an effectiveness trial designed to determine the magnitude and durability of protection from sexual transmission provided by ART over condom use. This study has the potential to provide definitive results critical to understanding the public health implications of ART.
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