Results from a PrEP Demonstration Project for At-Risk Cisgender Women in the United States.

BACKGROUND Daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) is effective for reducing HIV acquisition among cisgender women. We report results from the first United States observational open-label demonstration project of PrEP among at-risk cisgender women. METHODS Adherence Enhancement Guided by Individualized Texting and Drug Levels (AEGiS) was a 48-week single-arm open-label demonstration study of daily oral TDF/FTC in cisgender women ≥18 years old at-risk for HIV. Adherence was supported using two-way text messaging and titrated adherence counseling based on rapid-turnaround tenofovir diphosphate concentrations from dried blood spots. Study visits occurred at baseline, and at weeks 4, 12, and quarterly through week 48. Outcomes included TDF/FTC adherence, retention and persistence. RESULTS From June 2016 to October 2018, 136 cisgender women enrolled [mean age 40 (SD 11); 38% non-Hispanic (NH) Black and 19% Latina]. At 48 weeks, 84 (62%) participants were retained and 62 (46%) remained on PrEP. Over one-third (12/31) of those on study but off PrEP throughout study discontinued TDF/FTC due to side effects, and one adverse event led to study discontinuation. Of 120 participants with drug concentrations measured, 67 (56%) had at least one concentration consistent with ≥6 doses/week (d/w); 22 (18%) had consistent ≥6 d/w across all study visits attended. There were no incident HIV infections and 4 incident bacterial STIs. CONCLUSION Adequate PrEP adherence for protective drug concentrations was not achieved for most study participants. More work needs to be done to fully explicate the reasons for non-adherence and low retention in cisgender women.