Design challenges facing clinical trials of the effectiveness of new HIV-prevention technologies.

摘要

Several randomized placebo-controlled trials of micro-bicides or antiretroviral preexposure prophylaxis (PrEP) have been conducted to assess their effectiveness in preventing sexual transmission of HIV infection. Prior to 2010, none of these trials had demonstrated effectiveness in preventing HIV [1]. In July 2010, a microbicide gel containing the antiretroviral drug tenofovir (CAPRISA 004) demonstrated 39% reduction in HIV acquisition in women [2] and in November 2010, oral emtricitabine and tenofovir disoproxil fumarate (FTC-TDF) showed 44% reduction in HIV acquisition (iPrEx) in MSM [3]. Whereas oral FTC-TDF (FEM-PrEP) [4] and oral TDF (VOICE) [5] were not found to be effective in heterosexual women, two trials showed in July 2011 that oral TDF and FTC-TDF were found to reduce HIV transmission by 62 and 73% in serodiscordant couples (Partners PrEP trial) [6] and oral FTC-TDF reduced HIV transmission by 63% in heterosexual men and women (TDF2) [7].