Adherence and Acceptability in MTN 001: A Randomized Cross-Over Trial of Daily Oral and Topical Tenofovir for HIV Prevention in Women

We compared adherence to and acceptability of daily topical and oral formulations of tenofovir (TFV) used as pre-exposure prophylaxis (PrEP) for HIV prevention among women in South Africa, Uganda and the United States. 144 sexually active, HIV-uninfected women participated in a cross-over study of three regimens: oral tablet, vaginal gel, or both. We tested for differences in adherence and evaluated product acceptability. Self-reported adherence for all regimens was high (94 %), but serum TFV concentrations indicated only 64 % of participants used tablets consistently. Most women in the U.S. (72 %) favored tablets over gel; while preferences varied at the African sites (42 % preferred gel and 40 % tablets). Findings indicate a role for oral and vaginal PrEP formulations and highlight the importance of integrating pharmacokinetics-based adherence assessment in future trials. Biomedical HIV prevention interventions should consider geographic and cultural experience with product formulations, partner involvement, and sexual health benefits that ultimately influence use.