Increased Persistence, Re-Initiation of HIV Pre-Exposure Prophylaxis Found Among Patients Treated With Emtricitabine/Tenofovir Alafenamide

Open bottle of prescription PrEP Pills for Pre-Exposure Prophylaxis to help protect people from HIV.
Investigators conducted a study that compared the rate of persistence and re-initiation of HIV pre-exposure prophylaxis among patients treated with emtricitabine/tenofovir alafenamide vs those treated with emtricitabine/tenofovir disoproxil fumarate.

The following article is a part of conference coverage from the IDWeek 2021, being held virtually from September 29 to October 3, 2021. The team at Infectious Disease Advisor will be reporting on the latest news and research conducted by leading experts in the field. Check back for more from the IDWeek 2021.

An HIV pre-exposure prophylaxis (PrEP) regimen of emtricitabine/tenofovir alafenamide (F/TAF) was found to be associated with increased persistence and re-initiation compared with PrEP with emtricitabine/tenofovir disoproxil fumarate (F/TDF), according to research presented at IDWeek, held virtually from September 29 to October 3, 2021.

Investigators searched a de-identified prescription claims database to obtain data on patients who were negative for HIV infection and initiated PrEP with either F/TAF (n=82,402) or F/TDF (n=48,501) between October 2019 and December 2020. The investigators sought to assess PrEP persistence and re-initiation among patients treated with F/TAF vs those treated with F/TDF. A prescription fill gap of more than 30 days was defined as non-persistence, and a switch from F/TDF to F/TAF or from F/TAF to F/TDF was considered discontinuation.

Among patients included in the study, the median age at PrEP initiation was 35 (interquartile range [IQR], 28-47) years and 31 (IQR, 25-40) years among those treated with F/TAF and those treated with F/TDF, respectively. In addition, the median duration of PrEP persistence among patients treated with F/TAF vs those treated with F/TDF was 4 (IQR, 1.8-8.9) and 2 (IQR, 1.0-3.8) months, respectively. The investigators noted that medication persistence at days 60 and 90 was increased among patients treated with F/TAF vs those treated with F/TDF; however, PrEP discontinuation was 2.5 time more likely to occur among those treated with F/TDF. On analysis of the interaction between PrEP discontinuation and patient age, the investigators found that discontinuation of F/TDF was more significantly associated with older patients vs younger patients (P <.01).

Compared with patients treated with F/TAF, there was an increased rate of discontinuation observed among those who were prescribed F/TDF by an internal medicine or infectious disease physician rather than a family medicine physician. Re-initiation of PrEP was 1.7 times more likely to occur among patients treated with F/TAF, though no association was found between PrEP re-initiation and patient age.

According to the investigators, “these findings underscore the dynamic nature of PrEP utilization in the real-world and the importance of interventions aimed at improving PrEP persistence and re-initiation in people who would benefit from PrEP.”

Disclosure: Some author(s) declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures. 


Tao L, Shvachko V, Das M, et al. Persistence on F/TAF versus F/TDF for HIV pre-exposure prophylaxis: A real-world evidence analysis in the United States. Presented at: IDWeek; September 29 to October 3, 2021. Poster 855.

Visit Infectious Disease Advisor’s conference section for coverage of IDWeek 2021.