Recent news
November 2011
HIV prevention trial modified; Sponsor remains committed to HIV prevention research
November 29, 2011 -- The Microbicide Trials Network (MTN) has announced that a clinical trial to determine whether using daily antiretrovirals and a vaginal gel can help prevent HIV will be modified after researchers concluded the gel was not effective among study participants.
The VOICE study (Vaginal and Oral Interventions to Control the Epidemic) began in September 2009 to evaluate the safety and efficacy of the antiretrovirals tenofovir and Truvada®, taken daily as oral pre-exposure prophylaxis (PrEP) in women, as well as a vaginal microbicide containing tenofovir in gel form. The study included more than 5,000 HIV-negative women in South Africa, Uganda, and Zimbabwe. An independent data and safety monitoring board (DSMB) recently concluded that there was no difference in effectiveness between the tenofovir vaginal gel and a placebo gel. The DSMD found that while the gel is safe, participants using it had a six percent HIV incidence rate, the same as a group using the placebo gel.
In September 2011, another DSMB review recommended that women assigned to the tenofovir tablet should discontinue use of the product. According to the September 2011 DSMB review, the use of the tenofovir tablet would not demonstrate a difference in effectiveness between tenofovir and placebo. Neither decision reflected concerns around safety of use of tenofovir in either tablet or gel form.
The VOICE study is being conducted by the National Institutes of Health (NIH)-funded MTN. As the trial’s primary sponsor, the National Institute of Allergy and Infectious Diseases (NIAID) concurred with the DSMB's recommendation and has requested that the MTN discontinue use of tenofovir gel in the VOICE study.
Importantly, the DSMB review found no major safety concerns with the products. In fact, in a press release, NIAID stressed its commitment to the study and the importance of supporting research to develop new tools to help women prevent HIV infection.
“Although it is disappointing that the study first found oral tenofovir and now daily 1 percent tenofovir gel to be ineffective among the VOICE participants, NIAID recognizes the scientific importance of having clear outcomes and is pleased that the trial will continue to examine the question of whether oral Truvada is a safe and effective HIV prevention measure for women in this study,” the press release reads.
Yasmin Halima, director of GHTC member the Global Campaign for Microbicides (GCM), responded to the announcement in a GCM press release. “It’s not the answer we had hoped for, but it will provide more information to help us better understand what may or may not work.”
Gita Ramjee of the South African Medical Research Council—co-investigator for the VOICE South Africa trial site and member of GCM’s Steering Committee—agreed. “Even as we express our disappointment,” she said, “let us remember that the crucial insights we gain from VOICE will serve to advance the field. The urgency of the epidemic in my country—and its devastating impact on women—leaves no choice but for us to continue our search until we find effective tools to offer women as protection from HIV.”
