A study that meant to establish whether the daily use of oral Tenofovir, oral Truvada and a daily 1 percent vaginal Tenofovir gel could provide protection against HIV in women yielded disappointing results due to poor adherence of research participants.
The study, code-named VOICE used the two drugs (Tenofovir and Truvada), widely-used as antiretroviral medicines, to research into their safety and effectiveness as a form of pre-exposure prophylaxis (PrEP). Pre-exposure prophylaxis is a term used to mean a protection intervention used before exposure to sexual interaction.
The study was conducted among 5,029 women at 15 sites in Uganda, S. Africa and Zimbabwe women, regarded as having a high risk of contracting HIV in Uganda, Kenya, Zimbabwe and South Africa. In Uganda, the study recruited 322 women, who were followed up from September 2009 to June 2011 by the Makerere University-John Hopkins University (MU-JHU) Research Collaboration.
While presenting their study results on Monday, Samuel Kabwigu, part of the research team, said that though research proved that all three products used were safe, they were not effective in protecting the participants from HIV. This is most likely because most of the women did not take the study candidate-drugs as directed.
Adherence was measured by testing for the presence of the drugs in the participants’ bodies each time they visited the centre for follow up.
In her presentation, MU-JHU’s Dr. Clemensia Nakabiito said that though the study results are flat, they are clear in a way that daily use of these products was highly not acceptable among the women.
Though 91 percent of all the women remained in the study population to the end, there was a 2.1 incidence of HIV among the Ugandan women taking part in the study.
Nakabiito says that perhaps if more women had taken the drugs daily as directed, the study results would have been significantly different. She adds that as scientists they educate potential participants what is ethically required before a study commences, why the study is important, as well as why adherence is vital.
But Justice Sandra Kyagala from the National Community of Women Living with HIV, who took part in an HIV-related study conducted by the Medical Research Council in 1996, says that sometimes participants may not adhere, due to the complexity and demands of the study.
Kyagala says that though the scientists may follow the ethical study procedures, a little more effort may be needed for recruiting and retaining study participants in some communities.
The VOICE results from all the four countries were presented at the 20th Conference on Retroviruses and Opportunistic Infections (CROI) in Atlanta, USA on March 4th.
Though she acknowledged the results as disappointing, Mitchell Warren, the Executive Director for the Global Advocacy for HIV Prevention (AVAC), said that pre-exposure prophylaxis remains a valuable option for women, but the intervention works when used.
Proof that PrEP works, was the milestone Partners PrEP Study, conducted partly in Uganda, whose results were published in July 2011. The study proved that a daily dose of Truvada among people living with HIV, but in discordant couple relationships protected the HIV-free partner by up to 75 percent. The Food and Drug Administration (FDA) of the USA approved the use of this drug in July 2012.