Adherence to Pre-Exposure Prophylaxis for HIV Prevention in a Clinical Setting

Abstract

BackgroundThe HIV epidemic in the United States (US) disproportionately affects gay, bisexual, and other men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) using co-formulated tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) has demonstrated high efficacy in reducing HIV incidence among MSM. However, low adherence was reported in major efficacy trials and may present a substantial barrier to successful PrEP implementation. Rates of adherence to PrEP in “real-world” clinical settings in the US remain largely unknown.MethodsWe reviewed demographic and clinical data for the first 50 patients to enroll in a clinical PrEP program in Providence, Rhode Island. We analyzed self-reported drug adherence as well as drug concentrations in dried blood spots (DBS) from patients who attended either a three- or six-month follow-up appointment. We further assessed drug concentrations and the resistance profile of a single patient who seroconverted while taking PrEP.ResultsOf the first 50 patients to be prescribed PrEP, 62% attended a follow-up appointment at three months and 38% at six months. Of those who attended an appointment at either time point (70%, n = 35), 92% and 95% reported taking ±4 doses/week at three and six months, respectively. Drug concentrations were performed on a random sample of 20 of the 35 patients who attended a follow-up appointment. TDF levels consistent with ±4 doses/week were found in 90% of these patients. There was a significant correlation between self-reported adherence and drug concentrations (r = 0.49, p = 0.02). One patient who had been prescribed PrEP seroconverted at his three-month follow-up visit. The patient’s drug concentrations were consistent with daily dosing. Population sequencing and ultrasensitive allele-specific PCR detected the M184V mutation, but no other TDF- or FTC-associated mutations, including those present as minor variants.ConclusionIn this clinical PrEP program, adherence was high, and self-reported drug adherence accurately reflected drug concentrations as measured by DBS.

Implementation of Preexposure Prophylaxis for Human Immunodeficiency Virus Prevention Among Men Who Have Sex With Men at a New England Sexually Transmitted Diseases Clinic

“…The study evaluated PrEP initiation defined as receiving a prescription; subsequent retention in care and adherence were beyond the scope of this analysis but are reported elsewhere. 31,32 Additionally, patients may have sought PrEP care elsewhere after the PrEP education session, which we were not able to measure or incorporate in our analysis. On the level of clinic operations, we lost a significant number of PrEP candidates during the follow-up period.…”

Reaching Key Populations: PrEP Uptake in an Urban Health Care System in the Bronx, New York

“…Existing data on real-world PrEP uptake have been limited to specialized PrEP programs and demonstration projects (6, 7, 11). In addition, the population served in this study differs from prior studies in that it is predominantly non-Hispanic Black and Hispanic, key populations that have been disproportionately affected by the HIV epidemic in the U.S.…”

“…However, these studies have been largely limited to specialized PrEP programs and demonstration projects, and have focused mainly on men who have sex with men (MSM) (5-7). Little is known about PrEP initiation in large health care systems offering care across a spectrum of clinical settings such as primary care, subspecialty care, and sexual health centers.…”

Preexposure Prophylaxis—a New Addition to the Armamentarium Against Human Immunodeficiency Virus

“…4,5 Importantly, the overall development of resistance while on PrEP has been relatively low at 6% (305 total seroconversions). 33 M184V/I mutation was reported by all studies. According to Montgomery et al 33 mutations associated with TDF-FTC during PrEP decay rapidly and do not persist longer than 6 months after stopping PrEP.…”