Ethical considerations regarding oral preexposure prophylaxis in HIV prevention trials

Although substantial evidence supports oral preexposure prophylaxis with tenofovir disoproxil fumarate and emtricitabine (OPTF) for the primary prevention of HIV infection in certain settings, assessing whether other promising HIV prevention interventions are safe and effective as well as determining optimal prevention strategies necessitates research. However, given the established safety and efficacy of OPTF, it is necessary to determine when and how is it ethically acceptable to conduct this research, which is the focus of this review.

Although they are somewhat intertwined, questions regarding OPTF in research can be considered in two broad categories: use in a comparison arm and as a standard of prevention. Major statements addressing these issues are described and recent literature directed at the particular issue of OPTF in research is reviewed and critiqued.

There is now arguably a rebuttable presumption for the use of OPTF as a comparator or as part of the standard of prevention in much future HIV prevention research. However, making such determinations necessitates taking into account scientific considerations, the modality being evaluated, acceptability, adherence, and the local context. Doing so should be optimized by robust stakeholder engagement.